161611079880 has 128 divisors (see below), whose sum is σ = 488881008000. Its totient is φ = 42737436672.

The previous prime is 161611079869. The next prime is 161611079951. The reversal of 161611079880 is 88970116161.

It is a super-2 number, since 2×161611079880² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11489812 + ... + 11503868.

It is an arithmetic number, because the mean of its divisors is an integer number (3819382875).

Almost surely, 2^161611079880 is an apocalyptic number.

161611079880 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 161611079880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (244440504000).

161611079880 is an abundant number, since it is smaller than the sum of its proper divisors (327269928120).

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

161611079880 is a wasteful number, since it uses less digits than its factorization.

161611079880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14863 (or 14859 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 48.

The spelling of 161611079880 in words is "one hundred sixty-one billion, six hundred eleven million, seventy-nine thousand, eight hundred eighty".