31691648 has 16 divisors (see below), whose sum is σ = 63135960. Its totient is φ = 15845760.

The previous prime is 31691609. The next prime is 31691659. The reversal of 31691648 is 84619613.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123668 + ... + 123923.

Almost surely, 2^31691648 is an apocalyptic number.

It is an amenable number.

31691648 is a deficient number, since it is larger than the sum of its proper divisors (31444312).

31691648 is an equidigital number, since it uses as much as digits as its factorization.

31691648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247605 (or 247593 counting only the distinct ones).

The product of its digits is 31104, while the sum is 38.

The square root of 31691648 is about 5629.5335508370. The cubic root of 31691648 is about 316.4571708844.

The spelling of 31691648 in words is "thirty-one million, six hundred ninety-one thousand, six hundred forty-eight".