18313961 has 2 divisors, whose sum is σ = 18313962. Its totient is φ = 18313960.

The previous prime is 18313951. The next prime is 18313979. The reversal of 18313961 is 16931381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11323225 + 6990736 = 3365^2 + 2644^2 .

It is a cyclic number.

It is not a de Polignac number, because 18313961 - 2²² = 14119657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18313951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9156980 + 9156981.

It is an arithmetic number, because the mean of its divisors is an integer number (9156981).

Almost surely, 2^18313961 is an apocalyptic number.

It is an amenable number.

18313961 is a deficient number, since it is larger than the sum of its proper divisors (1).

18313961 is an equidigital number, since it uses as much as digits as its factorization.

18313961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 32.

The square root of 18313961 is about 4279.4813938140. The cubic root of 18313961 is about 263.5890885253.

The spelling of 18313961 in words is "eighteen million, three hundred thirteen thousand, nine hundred sixty-one".