18923131 has 2 divisors, whose sum is σ = 18923132. Its totient is φ = 18923130.

The previous prime is 18923123. The next prime is 18923137. The reversal of 18923131 is 13132981.

It is a strong prime.

It is an emirp because it is prime and its reverse (13132981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18923131 - 2³ = 18923123 is a prime.

It is a super-2 number, since 2×18923131² = 716169773686322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18923131.

It is not a weakly prime, because it can be changed into another prime (18923137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9461565 + 9461566.

It is an arithmetic number, because the mean of its divisors is an integer number (9461566).

Almost surely, 2^18923131 is an apocalyptic number.

18923131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18923131 is an equidigital number, since it uses as much as digits as its factorization.

18923131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 28.

The square root of 18923131 is about 4350.0725281310. The cubic root of 18923131 is about 266.4798234569.

The spelling of 18923131 in words is "eighteen million, nine hundred twenty-three thousand, one hundred thirty-one".