31639994 has 8 divisors (see below), whose sum is σ = 47488980. Its totient is φ = 15810336.

The previous prime is 31639969. The next prime is 31639999. The reversal of 31639994 is 49993613.

It can be written as a sum of positive squares in 2 ways, for example, as 21949225 + 9690769 = 4685^2 + 3113^2 .

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

It is not an unprimeable number, because it can be changed into a prime (31639999) 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, 392 + ... + 7964.

Almost surely, 2^31639994 is an apocalyptic number.

31639994 is a deficient number, since it is larger than the sum of its proper divisors (15848986).

31639994 is a wasteful number, since it uses less digits than its factorization.

31639994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9664.

The product of its digits is 157464, while the sum is 44.

The square root of 31639994 is about 5624.9439108315. The cubic root of 31639994 is about 316.2851469319.

The spelling of 31639994 in words is "thirty-one million, six hundred thirty-nine thousand, nine hundred ninety-four".