31905396 has 72 divisors (see below), whose sum is σ = 87764040. Its totient is φ = 9732096.

The previous prime is 31905361. The next prime is 31905397. The reversal of 31905396 is 69350913.

31905396 is a `hidden beast` number, since 31 + 90 + 539 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5588496 + 26316900 = 2364^2 + 5130^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 31905396.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31905397) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21940 + ... + 23348.

It is an arithmetic number, because the mean of its divisors is an integer number (1218945).

Almost surely, 2^31905396 is an apocalyptic number.

31905396 is a gapful number since it is divisible by the number (36) 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 31905396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43882020).

31905396 is an abundant number, since it is smaller than the sum of its proper divisors (55858644).

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

31905396 is a wasteful number, since it uses less digits than its factorization.

31905396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473 (or 1468 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 36.

The square root of 31905396 is about 5648.4861688775. The cubic root of 31905396 is about 317.1670380533.

The spelling of 31905396 in words is "thirty-one million, nine hundred five thousand, three hundred ninety-six".