18378959 has 2 divisors, whose sum is σ = 18378960. Its totient is φ = 18378958.

The previous prime is 18378937. The next prime is 18378967. The reversal of 18378959 is 95987381.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18378959 is a prime.

It is a super-2 number, since 2×18378959² = 675572267847362, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18378929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9189479 + 9189480.

It is an arithmetic number, because the mean of its divisors is an integer number (9189480).

Almost surely, 2^18378959 is an apocalyptic number.

18378959 is a deficient number, since it is larger than the sum of its proper divisors (1).

18378959 is an equidigital number, since it uses as much as digits as its factorization.

18378959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 50.

The square root of 18378959 is about 4287.0688121373. The cubic root of 18378959 is about 263.9005546401.

The spelling of 18378959 in words is "eighteen million, three hundred seventy-eight thousand, nine hundred fifty-nine".