31631643 has 12 divisors (see below), whose sum is σ = 45909448. Its totient is φ = 20986560.

The previous prime is 31631641. The next prime is 31631659. The reversal of 31631643 is 34613613.

31631643 is a `hidden beast` number, since 3 + 16 + 3 + 1 + 643 = 666.

It is not a de Polignac number, because 31631643 - 2¹ = 31631641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31631641) by changing a digit.

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 in 11 ways as a sum of consecutive naturals, for example, 6430 + ... + 10227.

Almost surely, 2^31631643 is an apocalyptic number.

31631643 is a deficient number, since it is larger than the sum of its proper divisors (14277805).

31631643 is a wasteful number, since it uses less digits than its factorization.

31631643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16874 (or 16871 counting only the distinct ones).

The product of its digits is 3888, while the sum is 27.

The square root of 31631643 is about 5624.2015433304. The cubic root of 31631643 is about 316.2573179161.

The spelling of 31631643 in words is "thirty-one million, six hundred thirty-one thousand, six hundred forty-three".