31940881 has 32 divisors (see below), whose sum is σ = 40632320. Its totient is φ = 24494400.

The previous prime is 31940837. The next prime is 31940899. The reversal of 31940881 is 18804913.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-31940881 is a prime.

It is a super-2 number, since 2×31940881² = 2040439758112322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31940801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 251440 + ... + 251566.

It is an arithmetic number, because the mean of its divisors is an integer number (1269760).

Almost surely, 2^31940881 is an apocalyptic number.

31940881 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

31940881 is a deficient number, since it is larger than the sum of its proper divisors (8691439).

31940881 is a wasteful number, since it uses less digits than its factorization.

31940881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 31940881 is about 5651.6264030808. The cubic root of 31940881 is about 317.2845782802.

The spelling of 31940881 in words is "thirty-one million, nine hundred forty thousand, eight hundred eighty-one".