19915165 has 4 divisors (see below), whose sum is σ = 23898204. Its totient is φ = 15932128.

The previous prime is 19915163. The next prime is 19915183. The reversal of 19915165 is 56151991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13227769 + 6687396 = 3637^2 + 2586^2 .

It is a cyclic number.

It is not a de Polignac number, because 19915165 - 2¹ = 19915163 is a prime.

It is a super-2 number, since 2×19915165² = 793227593954450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19915163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1991512 + ... + 1991521.

It is an arithmetic number, because the mean of its divisors is an integer number (5974551).

Almost surely, 2^19915165 is an apocalyptic number.

It is an amenable number.

19915165 is a deficient number, since it is larger than the sum of its proper divisors (3983039).

19915165 is an equidigital number, since it uses as much as digits as its factorization.

19915165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3983038.

The product of its digits is 12150, while the sum is 37.

The square root of 19915165 is about 4462.6410341859. The cubic root of 19915165 is about 271.0574216906.

The spelling of 19915165 in words is "nineteen million, nine hundred fifteen thousand, one hundred sixty-five".