165561501 has 16 divisors (see below), whose sum is σ = 252547200. Its totient is φ = 94507968.

The previous prime is 165561491. The next prime is 165561541. The reversal of 165561501 is 105165561.

It is not a de Polignac number, because 165561501 - 2⁵ = 165561469 is a prime.

It is a super-2 number, since 2×165561501² = 54821221226746002, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165561541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19735 + ... + 26843.

It is an arithmetic number, because the mean of its divisors is an integer number (15784200).

Almost surely, 2^165561501 is an apocalyptic number.

It is an amenable number.

165561501 is a deficient number, since it is larger than the sum of its proper divisors (86985699).

165561501 is a wasteful number, since it uses less digits than its factorization.

165561501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8228.

The product of its (nonzero) digits is 4500, while the sum is 30.

The square root of 165561501 is about 12867.0704124909. The cubic root of 165561501 is about 549.1021173609.

The spelling of 165561501 in words is "one hundred sixty-five million, five hundred sixty-one thousand, five hundred one".