165831659665920 has 3840 divisors, whose sum is σ = 695965055385600. Its totient is φ = 37563200962560.

The previous prime is 165831659665853. The next prime is 165831659665967. The reversal of 165831659665920 is 29566956138561.

165831659665920 is a `hidden beast` number, since 1 + 6 + 5 + 8 + 3 + 1 + 6 + 596 + 6 + 5 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (3840).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 492082075992 + ... + 492082076328.

It is an arithmetic number, because the mean of its divisors is an integer number (181240899840).

Almost surely, 2^{165831659665920} is an apocalyptic number.

165831659665920 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 165831659665920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (347982527692800).

165831659665920 is an abundant number, since it is smaller than the sum of its proper divisors (530133395719680).

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

165831659665920 is a wasteful number, since it uses less digits than its factorization.

165831659665920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 629856000, while the sum is 72.

The spelling of 165831659665920 in words is "one hundred sixty-five trillion, eight hundred thirty-one billion, six hundred fifty-nine million, six hundred sixty-five thousand, nine hundred twenty".