161957880 has 320 divisors, whose sum is σ = 642248640. Its totient is φ = 35831808.

The previous prime is 161957833. The next prime is 161957897. The reversal of 161957880 is 88759161.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 839064 + ... + 839256.

It is an arithmetic number, because the mean of its divisors is an integer number (2007027).

Almost surely, 2^161957880 is an apocalyptic number.

161957880 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 161957880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321124320).

161957880 is an abundant number, since it is smaller than the sum of its proper divisors (480290760).

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

161957880 is a wasteful number, since it uses less digits than its factorization.

161957880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

The square root of 161957880 is about 12726.2673239250. The cubic root of 161957880 is about 545.0889286191.

The spelling of 161957880 in words is "one hundred sixty-one million, nine hundred fifty-seven thousand, eight hundred eighty".