165561912 has 96 divisors (see below), whose sum is σ = 495499680. Its totient is φ = 49674240.

The previous prime is 165561887. The next prime is 165561923. The reversal of 165561912 is 219165561.

165561912 is a `hidden beast` number, since 1 + 6 + 5 + 561 + 91 + 2 = 666.

165561912 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25212 + ... + 31092.

It is an arithmetic number, because the mean of its divisors is an integer number (5161455).

Almost surely, 2^165561912 is an apocalyptic number.

165561912 is a gapful number since it is divisible by the number (12) 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 165561912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247749840).

165561912 is an abundant number, since it is smaller than the sum of its proper divisors (329937768).

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

165561912 is a wasteful number, since it uses less digits than its factorization.

165561912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5933 (or 5926 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 165561912 is about 12867.0863834825. The cubic root of 165561912 is about 549.1025717354.

The spelling of 165561912 in words is "one hundred sixty-five million, five hundred sixty-one thousand, nine hundred twelve".