31864645 has 4 divisors (see below), whose sum is σ = 38237580. Its totient is φ = 25491712.

The previous prime is 31864639. The next prime is 31864673. The reversal of 31864645 is 54646813.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54646813 = 13 ⋅4203601.

It can be written as a sum of positive squares in 2 ways, for example, as 9529569 + 22335076 = 3087^2 + 4726^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31864645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3186460 + ... + 3186469.

It is an arithmetic number, because the mean of its divisors is an integer number (9559395).

Almost surely, 2^31864645 is an apocalyptic number.

It is an amenable number.

31864645 is a deficient number, since it is larger than the sum of its proper divisors (6372935).

31864645 is an equidigital number, since it uses as much as digits as its factorization.

31864645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6372934.

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

The square root of 31864645 is about 5644.8777666128. The cubic root of 31864645 is about 317.0319472093.

The spelling of 31864645 in words is "thirty-one million, eight hundred sixty-four thousand, six hundred forty-five".