31905645904 has 120 divisors (see below), whose sum is σ = 70303446720. Its totient is φ = 14025739200.

The previous prime is 31905645901. The next prime is 31905645911. The reversal of 31905645904 is 40954650913.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31905645901) 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, 20464677 + ... + 20466235.

It is an arithmetic number, because the mean of its divisors is an integer number (585862056).

Almost surely, 2^31905645904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31905645904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35151723360).

31905645904 is an abundant number, since it is smaller than the sum of its proper divisors (38397800816).

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

31905645904 is a wasteful number, since it uses less digits than its factorization.

31905645904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662 (or 1603 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 46.

The spelling of 31905645904 in words is "thirty-one billion, nine hundred five million, six hundred forty-five thousand, nine hundred four".