161605501111080 has 256 divisors, whose sum is σ = 580593634790400. Its totient is φ = 39747496366080.

The previous prime is 161605501111063. The next prime is 161605501111091. The reversal of 161605501111080 is 80111105506161.

It is a happy number.

161605501111080 is a `hidden beast` number, since 1 + 6 + 1 + 6 + 0 + 550 + 1 + 11 + 10 + 80 = 666.

It is a super-2 number, since 2×161605501111080² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12608032 + ... + 21958448.

It is an arithmetic number, because the mean of its divisors is an integer number (2267943885900).

Almost surely, 2^{161605501111080} is an apocalyptic number.

161605501111080 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161605501111080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290296817395200).

161605501111080 is an abundant number, since it is smaller than the sum of its proper divisors (418988133679320).

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

161605501111080 is a wasteful number, since it uses less digits than its factorization.

161605501111080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9351681 (or 9351671 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 36.

The spelling of 161605501111080 in words is "one hundred sixty-one trillion, six hundred five billion, five hundred one million, one hundred eleven thousand, eighty".