165399520 has 96 divisors (see below), whose sum is σ = 459133920. Its totient is φ = 55511040.

The previous prime is 165399517. The next prime is 165399547. The reversal of 165399520 is 25993561.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (40).

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, 19266 + ... + 26494.

It is an arithmetic number, because the mean of its divisors is an integer number (4782645).

Almost surely, 2^165399520 is an apocalyptic number.

165399520 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 165399520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229566960).

165399520 is an abundant number, since it is smaller than the sum of its proper divisors (293734400).

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

165399520 is a wasteful number, since it uses less digits than its factorization.

165399520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7268 (or 7260 counting only the distinct ones).

The product of its (nonzero) digits is 72900, while the sum is 40.

The square root of 165399520 is about 12860.7744712362. The cubic root of 165399520 is about 548.9229832583.

The spelling of 165399520 in words is "one hundred sixty-five million, three hundred ninety-nine thousand, five hundred twenty".