165172644 has 144 divisors (see below), whose sum is σ = 519221248. Its totient is φ = 43110144.

The previous prime is 165172639. The next prime is 165172703. The reversal of 165172644 is 446271561.

165172644 is a `hidden beast` number, since 1 + 6 + 5 + 1 + 7 + 2 + 644 = 666.

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 = 165172599 and 165172608.

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 47 ways as a sum of consecutive naturals, for example, 415854 + ... + 416250.

Almost surely, 2^165172644 is an apocalyptic number.

165172644 is a gapful number since it is divisible by the number (14) 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 165172644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (259610624).

165172644 is an abundant number, since it is smaller than the sum of its proper divisors (354048604).

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

165172644 is a wasteful number, since it uses less digits than its factorization.

165172644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554 (or 549 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 165172644 is about 12851.9509802987. The cubic root of 165172644 is about 548.6718853184.

The spelling of 165172644 in words is "one hundred sixty-five million, one hundred seventy-two thousand, six hundred forty-four".