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311321540 = 225137113621
BaseRepresentation
bin10010100011100…
…110001111000100
3210200210202212102
4102203212033010
51114144242130
650520411232
710500121655
oct2243461704
9720722772
10311321540
1114a807532
1288316b18
134c66303a
142d4bd52c
151c4e8645
hex128e63c4

311321540 has 24 divisors (see below), whose sum is σ = 658553112. Its totient is φ = 123618560.

The previous prime is 311321539. The next prime is 311321551. The reversal of 311321540 is 45123113.

It can be written as a sum of positive squares in 4 ways, for example, as 39137536 + 272184004 = 6256^2 + 16498^2 .

It is a super-2 number, since 2×3113215402 = 193842202535943200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54071 + ... + 59550.

It is an arithmetic number, because the mean of its divisors is an integer number (27439713).

Almost surely, 2311321540 is an apocalyptic number.

It is an amenable number.

311321540 is an abundant number, since it is smaller than the sum of its proper divisors (347231572).

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

311321540 is a wasteful number, since it uses less digits than its factorization.

311321540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113767 (or 113765 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 311321540 is about 17644.3061637459. The cubic root of 311321540 is about 677.7503076049.

Adding to 311321540 its reverse (45123113), we get a palindrome (356444653).

The spelling of 311321540 in words is "three hundred eleven million, three hundred twenty-one thousand, five hundred forty".

Divisors: 1 2 4 5 10 20 137 274 548 685 1370 2740 113621 227242 454484 568105 1136210 2272420 15566077 31132154 62264308 77830385 155660770 311321540