31645864 has 8 divisors (see below), whose sum is σ = 59336010. Its totient is φ = 15822928.

The previous prime is 31645853. The next prime is 31645877. The reversal of 31645864 is 46854613.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 29268100 + 2377764 = 5410^2 + 1542^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

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, 1977859 + ... + 1977874.

Almost surely, 2^31645864 is an apocalyptic number.

It is an amenable number.

31645864 is a deficient number, since it is larger than the sum of its proper divisors (27690146).

31645864 is a wasteful number, since it uses less digits than its factorization.

31645864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3955739 (or 3955735 counting only the distinct ones).

The product of its digits is 69120, while the sum is 37.

The square root of 31645864 is about 5625.4656696135. The cubic root of 31645864 is about 316.3047052901.

The spelling of 31645864 in words is "thirty-one million, six hundred forty-five thousand, eight hundred sixty-four".