18666564 has 48 divisors (see below), whose sum is σ = 49996800. Its totient is φ = 5309856.

The previous prime is 18666563. The next prime is 18666623. The reversal of 18666564 is 46566681.

It is a super-2 number, since 2×18666564² = 696881223132192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (18666563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29847 + ... + 30465.

It is an arithmetic number, because the mean of its divisors is an integer number (1041600).

Almost surely, 2^18666564 is an apocalyptic number.

18666564 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18666564 is an abundant number, since it is smaller than the sum of its proper divisors (31330236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18666564 is a wasteful number, since it uses less digits than its factorization.

18666564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992 (or 990 counting only the distinct ones).

The product of its digits is 207360, while the sum is 42.

The square root of 18666564 is about 4320.4819175643. The cubic root of 18666564 is about 265.2699941963.

The spelling of 18666564 in words is "eighteen million, six hundred sixty-six thousand, five hundred sixty-four".