165561672 has 32 divisors (see below), whose sum is σ = 414960480. Its totient is φ = 55046400.

The previous prime is 165561661. The next prime is 165561679. The reversal of 165561672 is 276165561.

It is a self number, because there is not a number n which added to its sum of digits gives 165561672.

It is not an unprimeable number, because it can be changed into a prime (165561679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1023 + ... + 18225.

It is an arithmetic number, because the mean of its divisors is an integer number (12967515).

Almost surely, 2^165561672 is an apocalyptic number.

165561672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

165561672 is an abundant number, since it is smaller than the sum of its proper divisors (249398808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165561672 is a wasteful number, since it uses less digits than its factorization.

165561672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17613 (or 17609 counting only the distinct ones).

The product of its digits is 75600, while the sum is 39.

The square root of 165561672 is about 12867.0770573584. The cubic root of 165561672 is about 549.1023064073.

The spelling of 165561672 in words is "one hundred sixty-five million, five hundred sixty-one thousand, six hundred seventy-two".