165379675561 has 9 divisors (see below), whose sum is σ = 168580892389. Its totient is φ = 162238157536.

The previous prime is 165379675541. The next prime is 165379675597. The reversal of 165379675561 is 165576973561.

The square root of 165379675561 is 406669.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 20903665561 + 144476010000 = 144581^2 + 380100^2 .

It is not a de Polignac number, because 165379675561 - 2⁹ = 165379675049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165379675561.

It is not an unprimeable number, because it can be changed into a prime (165379675541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 21549621 + ... + 21557293.

Almost surely, 2^165379675561 is an apocalyptic number.

165379675561 is the 406669-th square number.

165379675561 is the 203335-th centered octagonal number.

It is an amenable number.

165379675561 is a deficient number, since it is larger than the sum of its proper divisors (3201216828).

165379675561 is an frugal number, since it uses more digits than its factorization.

165379675561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15452 (or 7726 counting only the distinct ones).

The product of its digits is 35721000, while the sum is 61.

The spelling of 165379675561 in words is "one hundred sixty-five billion, three hundred seventy-nine million, six hundred seventy-five thousand, five hundred sixty-one".