165621655175816 has 32 divisors (see below), whose sum is σ = 355172209754880. Its totient is φ = 70926976771200.

The previous prime is 165621655175813. The next prime is 165621655175831. The reversal of 165621655175816 is 618571556126561.

It is a happy number.

It is a hoax number, since the sum of its digits (65) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (165621655175813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1119354320 + ... + 1119502271.

It is an arithmetic number, because the mean of its divisors is an integer number (11099131554840).

Almost surely, 2^{165621655175816} is an apocalyptic number.

It is an amenable number.

165621655175816 is an abundant number, since it is smaller than the sum of its proper divisors (189550554579064).

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

165621655175816 is a wasteful number, since it uses less digits than its factorization.

165621655175816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2238857925 (or 2238857921 counting only the distinct ones).

The product of its digits is 90720000, while the sum is 65.

The spelling of 165621655175816 in words is "one hundred sixty-five trillion, six hundred twenty-one billion, six hundred fifty-five million, one hundred seventy-five thousand, eight hundred sixteen".