165644297280 has 1344 divisors, whose sum is σ = 753172992000. Its totient is φ = 32405667840.

The previous prime is 165644297279. The next prime is 165644297311. The reversal of 165644297280 is 82792446561.

165644297280 is a `hidden beast` number, since 1 + 6 + 56 + 442 + 9 + 72 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 276534421 + ... + 276535019.

Almost surely, 2^165644297280 is an apocalyptic number.

165644297280 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 165644297280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376586496000).

165644297280 is an abundant number, since it is smaller than the sum of its proper divisors (587528694720).

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

165644297280 is a wasteful number, since it uses less digits than its factorization.

165644297280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 54.

The spelling of 165644297280 in words is "one hundred sixty-five billion, six hundred forty-four million, two hundred ninety-seven thousand, two hundred eighty".