165869520 has 80 divisors (see below), whose sum is σ = 528120960. Its totient is φ = 43034112.

The previous prime is 165869519. The next prime is 165869569. The reversal of 165869520 is 25968561.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 460 + ... + 18219.

It is an arithmetic number, because the mean of its divisors is an integer number (6601512).

Almost surely, 2^165869520 is an apocalyptic number.

165869520 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 165869520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (264060480).

165869520 is an abundant number, since it is smaller than the sum of its proper divisors (362251440).

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

165869520 is a wasteful number, since it uses less digits than its factorization.

165869520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18732 (or 18726 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 42.

The square root of 165869520 is about 12879.0341252751. The cubic root of 165869520 is about 549.4424321964.

It can be divided in two parts, 16586 and 9520, that added together give a triangular number (26106 = T₂₂₈).

The spelling of 165869520 in words is "one hundred sixty-five million, eight hundred sixty-nine thousand, five hundred twenty".