165520665 has 48 divisors (see below), whose sum is σ = 302702400. Its totient is φ = 86743872.

The previous prime is 165520657. The next prime is 165520697. The reversal of 165520665 is 566025561.

It is a happy number.

It is not a de Polignac number, because 165520665 - 2³ = 165520657 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 70531 + ... + 72839.

It is an arithmetic number, because the mean of its divisors is an integer number (6306300).

Almost surely, 2^165520665 is an apocalyptic number.

165520665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165520665 is a deficient number, since it is larger than the sum of its proper divisors (137181735).

165520665 is an equidigital number, since it uses as much as digits as its factorization.

165520665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2388 (or 2376 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 165520665 is about 12865.4834732318. The cubic root of 165520665 is about 549.0569680201.

The spelling of 165520665 in words is "one hundred sixty-five million, five hundred twenty thousand, six hundred sixty-five".