18587961 has 20 divisors (see below), whose sum is σ = 31734912. Its totient is φ = 10621368.

The previous prime is 18587903. The next prime is 18587963. The reversal of 18587961 is 16978581.

18587961 is a `hidden beast` number, since 1 + 8 + 587 + 9 + 61 = 666.

It is not a de Polignac number, because 18587961 - 2²³ = 10199353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18587963) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15825 + ... + 16958.

Almost surely, 2^18587961 is an apocalyptic number.

It is an amenable number.

18587961 is a deficient number, since it is larger than the sum of its proper divisors (13146951).

18587961 is an equidigital number, since it uses as much as digits as its factorization.

18587961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32802 (or 32793 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 18587961 is about 4311.3757665042. The cubic root of 18587961 is about 264.8971286958.

The spelling of 18587961 in words is "eighteen million, five hundred eighty-seven thousand, nine hundred sixty-one".