31640636 has 6 divisors (see below), whose sum is σ = 55371120. Its totient is φ = 15820316.

The previous prime is 31640611. The next prime is 31640659. The reversal of 31640636 is 63604613.

It is a super-2 number, since 2×31640636² = 2002259692968992, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31640599 and 31640608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3955076 + ... + 3955083.

It is an arithmetic number, because the mean of its divisors is an integer number (9228520).

Almost surely, 2^31640636 is an apocalyptic number.

It is an amenable number.

31640636 is a deficient number, since it is larger than the sum of its proper divisors (23730484).

31640636 is a wasteful number, since it uses less digits than its factorization.

31640636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7910163 (or 7910161 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 29.

The square root of 31640636 is about 5625.0009777777. Note that the first 3 decimals coincide. The cubic root of 31640636 is about 316.2872861410.

The spelling of 31640636 in words is "thirty-one million, six hundred forty thousand, six hundred thirty-six".