165685538 has 4 divisors (see below), whose sum is σ = 248528310. Its totient is φ = 82842768.

The previous prime is 165685517. The next prime is 165685547. The reversal of 165685538 is 835586561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 835586561 = 739 ⋅1130699.

It can be written as a sum of positive squares in only one way, i.e., 162384049 + 3301489 = 12743^2 + 1817^2 .

It is a junction number, because it is equal to n+sod(n) for n = 165685492 and 165685501.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41421383 + ... + 41421386.

Almost surely, 2^165685538 is an apocalyptic number.

165685538 is a deficient number, since it is larger than the sum of its proper divisors (82842772).

165685538 is an equidigital number, since it uses as much as digits as its factorization.

165685538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82842771.

The product of its digits is 864000, while the sum is 47.

The square root of 165685538 is about 12871.8894494942. The cubic root of 165685538 is about 549.2392103790.

The spelling of 165685538 in words is "one hundred sixty-five million, six hundred eighty-five thousand, five hundred thirty-eight".