18957131 has 2 divisors, whose sum is σ = 18957132. Its totient is φ = 18957130.

The previous prime is 18957119. The next prime is 18957139. The reversal of 18957131 is 13175981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18957131 - 2⁶ = 18957067 is a prime.

It is a super-2 number, since 2×18957131² = 718745631502322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 18957091 and 18957100.

It is not a weakly prime, because it can be changed into another prime (18957139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9478565 + 9478566.

It is an arithmetic number, because the mean of its divisors is an integer number (9478566).

Almost surely, 2^18957131 is an apocalyptic number.

18957131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18957131 is an equidigital number, since it uses as much as digits as its factorization.

18957131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 35.

The square root of 18957131 is about 4353.9787551158. The cubic root of 18957131 is about 266.6393265373.

The spelling of 18957131 in words is "eighteen million, nine hundred fifty-seven thousand, one hundred thirty-one".