161899560 has 160 divisors (see below), whose sum is σ = 550424160. Its totient is φ = 42678144.

The previous prime is 161899559. The next prime is 161899571. The reversal of 161899560 is 65998161.

161899560 is a `hidden beast` number, since 1 + 6 + 1 + 89 + 9 + 560 = 666.

It is a super-2 number, since 2×161899560² = 52422935056387200, which contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 346447 + ... + 346913.

It is an arithmetic number, because the mean of its divisors is an integer number (3440151).

Almost surely, 2^161899560 is an apocalyptic number.

161899560 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 161899560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275212080).

161899560 is an abundant number, since it is smaller than the sum of its proper divisors (388524600).

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

161899560 is a wasteful number, since it uses less digits than its factorization.

161899560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597 (or 584 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 161899560 is about 12723.9757937525. The cubic root of 161899560 is about 545.0234930815.

The spelling of 161899560 in words is "one hundred sixty-one million, eight hundred ninety-nine thousand, five hundred sixty".