165511013 has 4 divisors (see below), whose sum is σ = 172707168. Its totient is φ = 158314860.

The previous prime is 165510991. The next prime is 165511039. The reversal of 165511013 is 310115561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165511013 - 2²⁶ = 98402149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 7196131 = 165511013 / (1 + 6 + 5 + 5 + 1 + 1 + 0 + 1 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165511013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165511043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3598043 + ... + 3598088.

It is an arithmetic number, because the mean of its divisors is an integer number (43176792).

Almost surely, 2^165511013 is an apocalyptic number.

It is an amenable number.

165511013 is a deficient number, since it is larger than the sum of its proper divisors (7196155).

165511013 is an equidigital number, since it uses as much as digits as its factorization.

165511013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7196154.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 165511013 is about 12865.1083555484. The cubic root of 165511013 is about 549.0462954336.

Adding to 165511013 its reverse (310115561), we get a palindrome (475626574).

The spelling of 165511013 in words is "one hundred sixty-five million, five hundred eleven thousand, thirteen".