18421379 has 2 divisors, whose sum is σ = 18421380. Its totient is φ = 18421378.

The previous prime is 18421357. The next prime is 18421399. The reversal of 18421379 is 97312481.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18421379 - 2²⁴ = 1644163 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (18421339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9210689 + 9210690.

It is an arithmetic number, because the mean of its divisors is an integer number (9210690).

Almost surely, 2^18421379 is an apocalyptic number.

18421379 is a deficient number, since it is larger than the sum of its proper divisors (1).

18421379 is an equidigital number, since it uses as much as digits as its factorization.

18421379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 18421379 is about 4292.0133969968. The cubic root of 18421379 is about 264.1034326496.

The spelling of 18421379 in words is "eighteen million, four hundred twenty-one thousand, three hundred seventy-nine".