31687396 has 12 divisors (see below), whose sum is σ = 59718652. Its totient is φ = 14624928.

The previous prime is 31687391. The next prime is 31687423. The reversal of 31687396 is 69378613.

It can be written as a sum of positive squares in 2 ways, for example, as 6687396 + 25000000 = 2586^2 + 5000^2 .

It is not an unprimeable number, because it can be changed into a prime (31687391) 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, 304635 + ... + 304738.

Almost surely, 2^31687396 is an apocalyptic number.

It is an amenable number.

31687396 is a deficient number, since it is larger than the sum of its proper divisors (28031256).

31687396 is a wasteful number, since it uses less digits than its factorization.

31687396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609390 (or 609388 counting only the distinct ones).

The product of its digits is 163296, while the sum is 43.

The square root of 31687396 is about 5629.1558869870. The cubic root of 31687396 is about 316.4430174596.

It can be divided in two parts, 316873 and 96, that added together give a square (316969 = 563²).

The spelling of 31687396 in words is "thirty-one million, six hundred eighty-seven thousand, three hundred ninety-six".