165642099520804 has 81 divisors (see below), whose sum is σ = 308908685532433. Its totient is φ = 77710691522464.

The previous prime is 165642099520801. The next prime is 165642099520811. The reversal of 165642099520804 is 408025990246561.

The square root of 165642099520804 is 12870202.

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

It can be written as a sum of positive squares in only one way, i.e., 119410911900900 + 46231187619904 = 10927530^2 + 6799352^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165642099520801) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 31377549837 + ... + 31377555115.

Almost surely, 2^{165642099520804} is an apocalyptic number.

165642099520804 is the 12870202-nd square number.

It is an amenable number.

165642099520804 is a deficient number, since it is larger than the sum of its proper divisors (143266586011629).

165642099520804 is an frugal number, since it uses more digits than its factorization.

165642099520804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10714 (or 5357 counting only the distinct ones).

The product of its (nonzero) digits is 37324800, while the sum is 61.

The spelling of 165642099520804 in words is "one hundred sixty-five trillion, six hundred forty-two billion, ninety-nine million, five hundred twenty thousand, eight hundred four".