165813120 has 192 divisors, whose sum is σ = 624864240. Its totient is φ = 40181760.

The previous prime is 165813113. The next prime is 165813139. The reversal of 165813120 is 21318561.

165813120 is a `hidden beast` number, since 1 + 658 + 1 + 3 + 1 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62052 + ... + 64668.

Almost surely, 2^165813120 is an apocalyptic number.

165813120 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 165813120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312432120).

165813120 is an abundant number, since it is smaller than the sum of its proper divisors (459051120).

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

165813120 is a wasteful number, since it uses less digits than its factorization.

165813120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2653 (or 2638 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 165813120 is about 12876.8443339197. The cubic root of 165813120 is about 549.3801501767.

It can be divided in two parts, 16581 and 3120, that added together give a triangular number (19701 = T₁₉₈).

The spelling of 165813120 in words is "one hundred sixty-five million, eight hundred thirteen thousand, one hundred twenty".