165139920 has 240 divisors, whose sum is σ = 626745600. Its totient is φ = 38599680.

The previous prime is 165139913. The next prime is 165139927. The reversal of 165139920 is 29931561.

It is an interprime number because it is at equal distance from previous prime (165139913) and next prime (165139927).

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165139927) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 229321 + ... + 230039.

It is an arithmetic number, because the mean of its divisors is an integer number (2611440).

Almost surely, 2^165139920 is an apocalyptic number.

165139920 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 165139920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313372800).

165139920 is an abundant number, since it is smaller than the sum of its proper divisors (461605680).

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

165139920 is a wasteful number, since it uses less digits than its factorization.

165139920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778 (or 769 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 165139920 is about 12850.6778031355. The cubic root of 165139920 is about 548.6356486386.

The spelling of 165139920 in words is "one hundred sixty-five million, one hundred thirty-nine thousand, nine hundred twenty".