165918637 has 2 divisors, whose sum is σ = 165918638. Its totient is φ = 165918636.

The previous prime is 165918631. The next prime is 165918647. The reversal of 165918637 is 736819561.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137499076 + 28419561 = 11726^2 + 5331^2 .

It is a cyclic number.

It is not a de Polignac number, because 165918637 - 2³ = 165918629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165918631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82959318 + 82959319.

It is an arithmetic number, because the mean of its divisors is an integer number (82959319).

Almost surely, 2^165918637 is an apocalyptic number.

It is an amenable number.

165918637 is a deficient number, since it is larger than the sum of its proper divisors (1).

165918637 is an equidigital number, since it uses as much as digits as its factorization.

165918637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 46.

The square root of 165918637 is about 12880.9408429664. The cubic root of 165918637 is about 549.4966601635.

The spelling of 165918637 in words is "one hundred sixty-five million, nine hundred eighteen thousand, six hundred thirty-seven".