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31023420 = 22351313947
BaseRepresentation
bin111011001011…
…0000100111100
32011101011010120
41312112010330
530420222140
63024534540
7524460201
oct166260474
964334116
1031023420
111656a39a
12a481450
136572a6c
144197ca8
152acc1d0
hex1d9613c

31023420 has 48 divisors (see below), whose sum is σ = 87550848. Its totient is φ = 8207680.

The previous prime is 31023407. The next prime is 31023437. The reversal of 31023420 is 2432013.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31023420.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 5887 + ... + 9833.

It is an arithmetic number, because the mean of its divisors is an integer number (1823976).

Almost surely, 231023420 is an apocalyptic number.

31023420 is a gapful number since it is divisible by the number (30) 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 31023420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43775424).

31023420 is an abundant number, since it is smaller than the sum of its proper divisors (56527428).

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

31023420 is a wasteful number, since it uses less digits than its factorization.

31023420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4090 (or 4088 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 31023420 is about 5569.8671438375. The cubic root of 31023420 is about 314.2171540729.

Adding to 31023420 its reverse (2432013), we get a palindrome (33455433).

The spelling of 31023420 in words is "thirty-one million, twenty-three thousand, four hundred twenty".

Divisors: 1 2 3 4 5 6 10 12 15 20 30 60 131 262 393 524 655 786 1310 1572 1965 2620 3930 3947 7860 7894 11841 15788 19735 23682 39470 47364 59205 78940 118410 236820 517057 1034114 1551171 2068228 2585285 3102342 5170570 6204684 7755855 10341140 15511710 31023420