165720 has 32 divisors (see below), whose sum is σ = 497520. Its totient is φ = 44160.

The previous prime is 165719. The next prime is 165721. The reversal of 165720 is 27561.

It is an interprime number because it is at equal distance from previous prime (165719) and next prime (165721).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 571 + ... + 810.

2¹⁶⁵⁷²⁰ is an apocalyptic number.

165720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165720 is an abundant number, since it is smaller than the sum of its proper divisors (331800).

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

165720 is a wasteful number, since it uses less digits than its factorization.

165720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395 (or 1391 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 165720 is about 407.0872142428. The cubic root of 165720 is about 54.9277287670.

The spelling of 165720 in words is "one hundred sixty-five thousand, seven hundred twenty".