18865619 has 2 divisors, whose sum is σ = 18865620. Its totient is φ = 18865618.

The previous prime is 18865607. The next prime is 18865661. The reversal of 18865619 is 91656881.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18865619 - 2²⁴ = 2088403 is a prime.

It is a super-2 number, since 2×18865619² = 711823160506322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18865619.

It is not a weakly prime, because it can be changed into another prime (18865669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9432809 + 9432810.

It is an arithmetic number, because the mean of its divisors is an integer number (9432810).

Almost surely, 2^18865619 is an apocalyptic number.

18865619 is a deficient number, since it is larger than the sum of its proper divisors (1).

18865619 is an equidigital number, since it uses as much as digits as its factorization.

18865619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 44.

The square root of 18865619 is about 4343.4570332858. The cubic root of 18865619 is about 266.2095838202.

The spelling of 18865619 in words is "eighteen million, eight hundred sixty-five thousand, six hundred nineteen".