165918638 has 8 divisors (see below), whose sum is σ = 250129200. Its totient is φ = 82542240.

The previous prime is 165918637. The next prime is 165918647. The reversal of 165918638 is 836819561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 165918592 and 165918601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165918631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208043 + ... + 208838.

It is an arithmetic number, because the mean of its divisors is an integer number (31266150).

Almost surely, 2^165918638 is an apocalyptic number.

165918638 is a deficient number, since it is larger than the sum of its proper divisors (84210562).

165918638 is a wasteful number, since it uses less digits than its factorization.

165918638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417082.

The product of its digits is 311040, while the sum is 47.

The square root of 165918638 is about 12880.9408817834. The cubic root of 165918638 is about 549.4966612675.

The spelling of 165918638 in words is "one hundred sixty-five million, nine hundred eighteen thousand, six hundred thirty-eight".