18385931 has 2 divisors, whose sum is σ = 18385932. Its totient is φ = 18385930.

The previous prime is 18385919. The next prime is 18385951. The reversal of 18385931 is 13958381.

It is a weak prime.

It is an emirp because it is prime and its reverse (13958381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18385931 - 2¹⁰ = 18384907 is a prime.

It is a super-2 number, since 2×18385931² = 676084917473522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18385951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9192965 + 9192966.

It is an arithmetic number, because the mean of its divisors is an integer number (9192966).

Almost surely, 2^18385931 is an apocalyptic number.

18385931 is a deficient number, since it is larger than the sum of its proper divisors (1).

18385931 is an equidigital number, since it uses as much as digits as its factorization.

18385931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The square root of 18385931 is about 4287.8818780372. The cubic root of 18385931 is about 263.9339203685.

The spelling of 18385931 in words is "eighteen million, three hundred eighty-five thousand, nine hundred thirty-one".