31997638 has 16 divisors (see below), whose sum is σ = 50925024. Its totient is φ = 15026560.

The previous prime is 31997627. The next prime is 31997683. The reversal of 31997638 is 83679913.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29628 + ... + 30688.

It is an arithmetic number, because the mean of its divisors is an integer number (3182814).

Almost surely, 2^31997638 is an apocalyptic number.

31997638 is a deficient number, since it is larger than the sum of its proper divisors (18927386).

31997638 is a wasteful number, since it uses less digits than its factorization.

31997638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1967.

The product of its digits is 244944, while the sum is 46.

The square root of 31997638 is about 5656.6454723626. The cubic root of 31997638 is about 317.4723988654.

The spelling of 31997638 in words is "thirty-one million, nine hundred ninety-seven thousand, six hundred thirty-eight".