165591613 has 8 divisors (see below), whose sum is σ = 185528160. Its totient is φ = 146468880.

The previous prime is 165591599. The next prime is 165591619. The reversal of 165591613 is 316195561.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165591613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165591619) 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, 203023 + ... + 203836.

It is an arithmetic number, because the mean of its divisors is an integer number (23191020).

Almost surely, 2^165591613 is an apocalyptic number.

It is an amenable number.

165591613 is a deficient number, since it is larger than the sum of its proper divisors (19936547).

165591613 is a wasteful number, since it uses less digits than its factorization.

165591613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406907.

The product of its digits is 24300, while the sum is 37.

The square root of 165591613 is about 12868.2404780141. The cubic root of 165591613 is about 549.1354052137.

The spelling of 165591613 in words is "one hundred sixty-five million, five hundred ninety-one thousand, six hundred thirteen".