18643964 has 12 divisors (see below), whose sum is σ = 32772264. Its totient is φ = 9280464.

The previous prime is 18643949. The next prime is 18643991. The reversal of 18643964 is 46934681.

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, 9359 + ... + 11174.

It is an arithmetic number, because the mean of its divisors is an integer number (2731022).

Almost surely, 2^18643964 is an apocalyptic number.

It is an amenable number.

18643964 is a deficient number, since it is larger than the sum of its proper divisors (14128300).

18643964 is a wasteful number, since it uses less digits than its factorization.

18643964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20764 (or 20762 counting only the distinct ones).

The product of its digits is 124416, while the sum is 41.

The square root of 18643964 is about 4317.8656764656. The cubic root of 18643964 is about 265.1628949829.

The spelling of 18643964 in words is "eighteen million, six hundred forty-three thousand, nine hundred sixty-four".