165611161000000 has 441 divisors, whose sum is σ = 436950678893313. Its totient is φ = 62265369600000.

The previous prime is 165611160999959. The next prime is 165611161000063. The reversal of 165611161000000 is 161116561.

The square root of 165611161000000 is 12869000.

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

It can be written as a sum of positive squares in 31 ways, for example, as 80927584192576 + 84683576807424 = 8995976^2 + 9202368^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 218772999622 + ... + 218773000378.

Almost surely, 2^{165611161000000} is an apocalyptic number.

165611161000000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

165611161000000 is the 12869000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165611161000000

165611161000000 is an abundant number, since it is smaller than the sum of its proper divisors (271339517893313).

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

165611161000000 is an frugal number, since it uses more digits than its factorization.

165611161000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1590 (or 781 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 28.

The spelling of 165611161000000 in words is "one hundred sixty-five trillion, six hundred eleven billion, one hundred sixty-one million", and thus it is an aban number.