18660400 has 60 divisors (see below), whose sum is σ = 48918744. Its totient is φ = 6784000.

The previous prime is 18660377. The next prime is 18660401. The reversal of 18660400 is 406681.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (18660401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2280 + ... + 6520.

Almost surely, 2^18660400 is an apocalyptic number.

18660400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18660400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24459372).

18660400 is an abundant number, since it is smaller than the sum of its proper divisors (30258344).

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

18660400 is a wasteful number, since it uses less digits than its factorization.

18660400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4270 (or 4259 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 18660400 is about 4319.7685123164. The cubic root of 18660400 is about 265.2407921739.

The spelling of 18660400 in words is "eighteen million, six hundred sixty thousand, four hundred".