31955681 has 4 divisors (see below), whose sum is σ = 31981872. Its totient is φ = 31929492.

The previous prime is 31955669. The next prime is 31955689. The reversal of 31955681 is 18655913.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31955681 is a prime.

It is a super-2 number, since 2×31955681² = 2042331096347522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31955689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11171 + ... + 13736.

It is an arithmetic number, because the mean of its divisors is an integer number (7995468).

Almost surely, 2^31955681 is an apocalyptic number.

It is an amenable number.

31955681 is a deficient number, since it is larger than the sum of its proper divisors (26191).

31955681 is a wasteful number, since it uses less digits than its factorization.

31955681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26190.

The product of its digits is 32400, while the sum is 38.

The square root of 31955681 is about 5652.9356090442. The cubic root of 31955681 is about 317.3335759547. Note that the first 3 decimals are identical.

The spelling of 31955681 in words is "thirty-one million, nine hundred fifty-five thousand, six hundred eighty-one".