165521818725120 has 2016 divisors, whose sum is σ = 702903501082944. Its totient is φ = 36799266816000.

The previous prime is 165521818725119. The next prime is 165521818725163. The reversal of 165521818725120 is 21527818125561.

165521818725120 is a `hidden beast` number, since 1 + 6 + 5 + 52 + 1 + 8 + 1 + 8 + 72 + 512 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 20949473170 + ... + 20949481070.

It is an arithmetic number, because the mean of its divisors is an integer number (348662450934).

Almost surely, 2^{165521818725120} is an apocalyptic number.

165521818725120 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 165521818725120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351451750541472).

165521818725120 is an abundant number, since it is smaller than the sum of its proper divisors (537381682357824).

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

165521818725120 is a wasteful number, since it uses less digits than its factorization.

165521818725120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8121 (or 8092 counting only the distinct ones).

The product of its (nonzero) digits is 2688000, while the sum is 54.

The spelling of 165521818725120 in words is "one hundred sixty-five trillion, five hundred twenty-one billion, eight hundred eighteen million, seven hundred twenty-five thousand, one hundred twenty".