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131311440 = 243251314029
BaseRepresentation
bin1111101001110…
…10011101010000
3100011002022102200
413310322131100
5232103431230
621010243200
73153062121
oct764723520
9304068380
10131311440
1168138257
1237b86500
13212876a0
1413622048
15b7dc160
hex7d3a750

131311440 has 120 divisors (see below), whose sum is σ = 474943560. Its totient is φ = 32320512.

The previous prime is 131311423. The next prime is 131311457. The reversal of 131311440 is 44113131.

It is an interprime number because it is at equal distance from previous prime (131311423) and next prime (131311457).

It can be written as a sum of positive squares in 4 ways, for example, as 4613904 + 126697536 = 2148^2 + 11256^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2346 + ... + 16374.

It is an arithmetic number, because the mean of its divisors is an integer number (3957863).

Almost surely, 2131311440 is an apocalyptic number.

131311440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131311440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237471780).

131311440 is an abundant number, since it is smaller than the sum of its proper divisors (343632120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131311440 is a wasteful number, since it uses less digits than its factorization.

131311440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14061 (or 14052 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 131311440 is about 11459.1203850906. The cubic root of 131311440 is about 508.2774643129.

Adding to 131311440 its reverse (44113131), we get a palindrome (175424571).

The spelling of 131311440 in words is "one hundred thirty-one million, three hundred eleven thousand, four hundred forty".

Divisors: 1 2 3 4 5 6 8 9 10 12 13 15 16 18 20 24 26 30 36 39 40 45 48 52 60 65 72 78 80 90 104 117 120 130 144 156 180 195 208 234 240 260 312 360 390 468 520 585 624 720 780 936 1040 1170 1560 1872 2340 3120 4680 9360 14029 28058 42087 56116 70145 84174 112232 126261 140290 168348 182377 210435 224464 252522 280580 336696 364754 420870 505044 547131 561160 631305 673392 729508 841740 911885 1010088 1094262 1122320 1262610 1459016 1641393 1683480 1823770 2020176 2188524 2525220 2735655 2918032 3282786 3366960 3647540 4377048 5050440 5471310 6565572 7295080 8206965 8754096 10100880 10942620 13131144 14590160 16413930 21885240 26262288 32827860 43770480 65655720 131311440