18421366 has 4 divisors (see below), whose sum is σ = 27632052. Its totient is φ = 9210682.

The previous prime is 18421357. The next prime is 18421379. The reversal of 18421366 is 66312481.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4605340 + ... + 4605343.

It is an arithmetic number, because the mean of its divisors is an integer number (6908013).

Almost surely, 2^18421366 is an apocalyptic number.

18421366 is a deficient number, since it is larger than the sum of its proper divisors (9210686).

18421366 is an equidigital number, since it uses as much as digits as its factorization.

18421366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9210685.

The product of its digits is 6912, while the sum is 31.

The square root of 18421366 is about 4292.0118825558. The cubic root of 18421366 is about 264.1033705234.

The spelling of 18421366 in words is "eighteen million, four hundred twenty-one thousand, three hundred sixty-six".