18561964 has 6 divisors (see below), whose sum is σ = 32483444. Its totient is φ = 9280980.

The previous prime is 18561941. The next prime is 18561967. The reversal of 18561964 is 46916581.

It is not an unprimeable number, because it can be changed into a prime (18561967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2320242 + ... + 2320249.

Almost surely, 2^18561964 is an apocalyptic number.

It is an amenable number.

18561964 is a deficient number, since it is larger than the sum of its proper divisors (13921480).

18561964 is a wasteful number, since it uses less digits than its factorization.

18561964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4640495 (or 4640493 counting only the distinct ones).

The product of its digits is 51840, while the sum is 40.

The square root of 18561964 is about 4308.3597807054. The cubic root of 18561964 is about 264.7735766176.

The spelling of 18561964 in words is "eighteen million, five hundred sixty-one thousand, nine hundred sixty-four".