165720613 has 8 divisors (see below), whose sum is σ = 167207040. Its totient is φ = 164240400.

The previous prime is 165720601. The next prime is 165720623. The reversal of 165720613 is 316027561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165720613 - 2⁹ = 165720101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165720623) 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, 63688 + ... + 66238.

It is an arithmetic number, because the mean of its divisors is an integer number (20900880).

Almost surely, 2^165720613 is an apocalyptic number.

It is an amenable number.

165720613 is a deficient number, since it is larger than the sum of its proper divisors (1486427).

165720613 is a wasteful number, since it uses less digits than its factorization.

165720613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3107.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 165720613 is about 12873.2518424833. The cubic root of 165720613 is about 549.2779649303.

The spelling of 165720613 in words is "one hundred sixty-five million, seven hundred twenty thousand, six hundred thirteen".