161791560 has 128 divisors (see below), whose sum is σ = 616377600. Its totient is φ = 36979200.

The previous prime is 161791547. The next prime is 161791571. The reversal of 161791560 is 65197161.

It is a happy number.

161791560 is a `hidden beast` number, since 1 + 6 + 1 + 7 + 91 + 560 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3141 + ... + 18260.

It is an arithmetic number, because the mean of its divisors is an integer number (4815450).

Almost surely, 2^161791560 is an apocalyptic number.

161791560 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 161791560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308188800).

161791560 is an abundant number, since it is smaller than the sum of its proper divisors (454586040).

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

161791560 is a wasteful number, since it uses less digits than its factorization.

161791560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21428 (or 21418 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 36.

The square root of 161791560 is about 12719.7311292338. The cubic root of 161791560 is about 544.9022746528.

The spelling of 161791560 in words is "one hundred sixty-one million, seven hundred ninety-one thousand, five hundred sixty".