18373866 has 16 divisors (see below), whose sum is σ = 41997504. Its totient is φ = 5249664.

The previous prime is 18373829. The next prime is 18373891. The reversal of 18373866 is 66837381.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 437473 = 18373866 / (1 + 8 + 3 + 7 + 3 + 8 + 6 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 218695 + ... + 218778.

It is an arithmetic number, because the mean of its divisors is an integer number (2624844).

Almost surely, 2^18373866 is an apocalyptic number.

18373866 is an abundant number, since it is smaller than the sum of its proper divisors (23623638).

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

18373866 is a wasteful number, since it uses less digits than its factorization.

18373866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437485.

The product of its digits is 145152, while the sum is 42.

The square root of 18373866 is about 4286.4747753836. The cubic root of 18373866 is about 263.8761758620.

The spelling of 18373866 in words is "eighteen million, three hundred seventy-three thousand, eight hundred sixty-six".