31689931 has 8 divisors (see below), whose sum is σ = 39003104. Its totient is φ = 25073280.

The previous prime is 31689923. The next prime is 31689941. The reversal of 31689931 is 13998613.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31689931 - 2³ = 31689923 is a prime.

It is a super-2 number, since 2×31689931² = 2008503453569522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31689941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174030 + ... + 174211.

It is an arithmetic number, because the mean of its divisors is an integer number (4875388).

Almost surely, 2^31689931 is an apocalyptic number.

31689931 is a deficient number, since it is larger than the sum of its proper divisors (7313173).

31689931 is a wasteful number, since it uses less digits than its factorization.

31689931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348261.

The product of its digits is 34992, while the sum is 40.

The square root of 31689931 is about 5629.3810494583. The cubic root of 31689931 is about 316.4514557427.

The spelling of 31689931 in words is "thirty-one million, six hundred eighty-nine thousand, nine hundred thirty-one".