31643812 has 6 divisors (see below), whose sum is σ = 55376678. Its totient is φ = 15821904.

The previous prime is 31643789. The next prime is 31643813. The reversal of 31643812 is 21834613.

It can be written as a sum of positive squares in only one way, i.e., 18870336 + 12773476 = 4344^2 + 3574^2 .

It is not an unprimeable number, because it can be changed into a prime (31643813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3955473 + ... + 3955480.

Almost surely, 2^31643812 is an apocalyptic number.

It is an amenable number.

31643812 is a deficient number, since it is larger than the sum of its proper divisors (23732866).

31643812 is a wasteful number, since it uses less digits than its factorization.

31643812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7910957 (or 7910955 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 31643812 is about 5625.2832817557. The cubic root of 31643812 is about 316.2978684695.

The spelling of 31643812 in words is "thirty-one million, six hundred forty-three thousand, eight hundred twelve".