165564720 has 120 divisors (see below), whose sum is σ = 559022256. Its totient is φ = 43912704.

The previous prime is 165564703. The next prime is 165564731. The reversal of 165564720 is 27465561.

It is a happy number.

165564720 is a `hidden beast` number, since 1 + 6 + 5 + 5 + 647 + 2 + 0 = 666.

165564720 is digitally balanced in base 3, 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 (120).

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

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 23 ways as a sum of consecutive naturals, for example, 162934 + ... + 163946.

Almost surely, 2^165564720 is an apocalyptic number.

165564720 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 165564720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279511128).

165564720 is an abundant number, since it is smaller than the sum of its proper divisors (393457536).

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

165564720 is a wasteful number, since it uses less digits than its factorization.

165564720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1259 (or 1250 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 165564720 is about 12867.1954986314. The cubic root of 165564720 is about 549.1056760551.

The spelling of 165564720 in words is "one hundred sixty-five million, five hundred sixty-four thousand, seven hundred twenty".