165561228 has 36 divisors (see below), whose sum is σ = 478288720. Its totient is φ = 47303136.

The previous prime is 165561131. The next prime is 165561233. The reversal of 165561228 is 822165561.

165561228 is a `hidden beast` number, since 16 + 5 + 5 + 612 + 28 = 666.

165561228 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 165561192 and 165561201.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 328243 + ... + 328746.

Almost surely, 2^165561228 is an apocalyptic number.

165561228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

165561228 is an abundant number, since it is smaller than the sum of its proper divisors (312727492).

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

165561228 is a wasteful number, since it uses less digits than its factorization.

165561228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657006 (or 657001 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 165561228 is about 12867.0598040112. The cubic root of 165561228 is about 549.1018155497.

The spelling of 165561228 in words is "one hundred sixty-five million, five hundred sixty-one thousand, two hundred twenty-eight".