165561099664 has 15 divisors (see below), whose sum is σ = 320777784043. Its totient is φ = 82779736048.

The previous prime is 165561099643. The next prime is 165561099677. The reversal of 165561099664 is 466990165561.

The square root of 165561099664 is 406892.

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

It is a super-3 number, since 3×165561099664³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165561099599 and 165561099608.

It is an unprimeable number.

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 2 ways as a sum of consecutive naturals, for example, 1576707 + ... + 1678429.

Almost surely, 2^165561099664 is an apocalyptic number.

165561099664 is the 406892-nd square number.

It is an amenable number.

165561099664 is a deficient number, since it is larger than the sum of its proper divisors (155216684379).

165561099664 is an frugal number, since it uses more digits than its factorization.

165561099664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203454 (or 101725 counting only the distinct ones).

The product of its (nonzero) digits is 10497600, while the sum is 58.

The spelling of 165561099664 in words is "one hundred sixty-five billion, five hundred sixty-one million, ninety-nine thousand, six hundred sixty-four".