161688080 has 40 divisors (see below), whose sum is σ = 380165400. Its totient is φ = 63945728.

The previous prime is 161688073. The next prime is 161688083. The reversal of 161688080 is 80886161.

It can be written as a sum of positive squares in 4 ways, for example, as 6635776 + 155052304 = 2576^2 + 12452^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×161688080² = 52286070428172800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161688083) 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, 4235 + ... + 18474.

It is an arithmetic number, because the mean of its divisors is an integer number (9504135).

Almost surely, 2^161688080 is an apocalyptic number.

161688080 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161688080 is an abundant number, since it is smaller than the sum of its proper divisors (218477320).

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

161688080 is a wasteful number, since it uses less digits than its factorization.

161688080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22811 (or 22805 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 161688080 is about 12715.6627825686. The cubic root of 161688080 is about 544.7860788244.

The spelling of 161688080 in words is "one hundred sixty-one million, six hundred eighty-eight thousand, eighty".