18957161 has 2 divisors, whose sum is σ = 18957162. Its totient is φ = 18957160.

The previous prime is 18957149. The next prime is 18957179. The reversal of 18957161 is 16175981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11833600 + 7123561 = 3440^2 + 2669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18957161 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18957131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9478580 + 9478581.

It is an arithmetic number, because the mean of its divisors is an integer number (9478581).

Almost surely, 2^18957161 is an apocalyptic number.

It is an amenable number.

18957161 is a deficient number, since it is larger than the sum of its proper divisors (1).

18957161 is an equidigital number, since it uses as much as digits as its factorization.

18957161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 38.

The square root of 18957161 is about 4353.9822002392. The cubic root of 18957161 is about 266.6394671911.

The spelling of 18957161 in words is "eighteen million, nine hundred fifty-seven thousand, one hundred sixty-one".