161866560 has 112 divisors (see below), whose sum is σ = 519232896. Its totient is φ = 42719232.

The previous prime is 161866553. The next prime is 161866561. The reversal of 161866560 is 65668161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161866561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98062 + ... + 99698.

It is an arithmetic number, because the mean of its divisors is an integer number (4636008).

Almost surely, 2^161866560 is an apocalyptic number.

161866560 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 161866560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (259616448).

161866560 is an abundant number, since it is smaller than the sum of its proper divisors (357366336).

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

161866560 is a wasteful number, since it uses less digits than its factorization.

161866560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760 (or 1750 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 161866560 is about 12722.6789631744. The cubic root of 161866560 is about 544.9864598381.

The spelling of 161866560 in words is "one hundred sixty-one million, eight hundred sixty-six thousand, five hundred sixty".