165688975616 has 18 divisors (see below), whose sum is σ = 330730729182. Its totient is φ = 82844487680.

The previous prime is 165688975609. The next prime is 165688975633. The reversal of 165688975616 is 616579886561.

It can be written as a sum of positive squares in only one way, i.e., 136379535616 + 29309440000 = 369296^2 + 171200^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323611025 + ... + 323611536.

It is an arithmetic number, because the mean of its divisors is an integer number (18373929399).

Almost surely, 2^165688975616 is an apocalyptic number.

165688975616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

165688975616 is a deficient number, since it is larger than the sum of its proper divisors (165041753566).

165688975616 is an frugal number, since it uses more digits than its factorization.

165688975616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647222577 (or 647222563 counting only the distinct ones).

The product of its digits is 130636800, while the sum is 68.

The spelling of 165688975616 in words is "one hundred sixty-five billion, six hundred eighty-eight million, nine hundred seventy-five thousand, six hundred sixteen".