161651166624 has 72 divisors (see below), whose sum is σ = 460438655040. Its totient is φ = 53796613248.

The previous prime is 161651166617. The next prime is 161651166629. The reversal of 161651166624 is 426661156161.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×161651166624² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161651166624.

It is not an unprimeable number, because it can be changed into a prime (161651166629) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 275112 + ... + 631655.

It is an arithmetic number, because the mean of its divisors is an integer number (6394981320).

Almost surely, 2^161651166624 is an apocalyptic number.

It is an amenable number.

161651166624 is an abundant number, since it is smaller than the sum of its proper divisors (298787488416).

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

161651166624 is a wasteful number, since it uses less digits than its factorization.

161651166624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907402 (or 907391 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The spelling of 161651166624 in words is "one hundred sixty-one billion, six hundred fifty-one million, one hundred sixty-six thousand, six hundred twenty-four".