18421619 has 2 divisors, whose sum is σ = 18421620. Its totient is φ = 18421618.

The previous prime is 18421609. The next prime is 18421631. The reversal of 18421619 is 91612481.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18421619 - 2²⁰ = 17373043 is a prime.

It is a super-2 number, since 2×18421619² = 678712093162322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18421609) 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 as a sum of consecutive naturals, namely, 9210809 + 9210810.

It is an arithmetic number, because the mean of its divisors is an integer number (9210810).

Almost surely, 2^18421619 is an apocalyptic number.

18421619 is a deficient number, since it is larger than the sum of its proper divisors (1).

18421619 is an equidigital number, since it uses as much as digits as its factorization.

18421619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 32.

The square root of 18421619 is about 4292.0413558119. The cubic root of 18421619 is about 264.1045795877.

The spelling of 18421619 in words is "eighteen million, four hundred twenty-one thousand, six hundred nineteen".