18366920 has 128 divisors (see below), whose sum is σ = 51408000. Its totient is φ = 5840640.

The previous prime is 18366913. The next prime is 18366923. The reversal of 18366920 is 2966381.

18366920 = 285² + 286² + ... + 427².

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (18366923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 966671 + ... + 966689.

It is an arithmetic number, because the mean of its divisors is an integer number (401625).

Almost surely, 2^18366920 is an apocalyptic number.

18366920 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 18366920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25704000).

18366920 is an abundant number, since it is smaller than the sum of its proper divisors (33041080).

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

18366920 is a wasteful number, since it uses less digits than its factorization.

18366920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 18366920 is about 4285.6644759010. The cubic root of 18366920 is about 263.8429200240.

The spelling of 18366920 in words is "eighteen million, three hundred sixty-six thousand, nine hundred twenty".