18386421 has 8 divisors (see below), whose sum is σ = 24791040. Its totient is φ = 12119712.

The previous prime is 18386399. The next prime is 18386449. The reversal of 18386421 is 12468381.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18386421 - 2⁷ = 18386293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18386461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34165 + ... + 34698.

It is an arithmetic number, because the mean of its divisors is an integer number (3098880).

Almost surely, 2^18386421 is an apocalyptic number.

It is an amenable number.

18386421 is a deficient number, since it is larger than the sum of its proper divisors (6404619).

18386421 is an equidigital number, since it uses as much as digits as its factorization.

18386421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68955.

The product of its digits is 9216, while the sum is 33.

The square root of 18386421 is about 4287.9390154245. The cubic root of 18386421 is about 263.9362650321.

The spelling of 18386421 in words is "eighteen million, three hundred eighty-six thousand, four hundred twenty-one".