16642165 has 4 divisors (see below), whose sum is σ = 19970604. Its totient is φ = 13313728.

The previous prime is 16642151. The next prime is 16642177. The reversal of 16642165 is 56124661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56124661 = 181 ⋅310081.

It can be written as a sum of positive squares in 2 ways, for example, as 1965604 + 14676561 = 1402^2 + 3831^2 .

It is a cyclic number.

It is not a de Polignac number, because 16642165 - 2¹⁷ = 16511093 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1664212 + ... + 1664221.

It is an arithmetic number, because the mean of its divisors is an integer number (4992651).

Almost surely, 2^16642165 is an apocalyptic number.

It is an amenable number.

16642165 is a deficient number, since it is larger than the sum of its proper divisors (3328439).

16642165 is an equidigital number, since it uses as much as digits as its factorization.

16642165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3328438.

The product of its digits is 8640, while the sum is 31.

The square root of 16642165 is about 4079.4809718885. The cubic root of 16642165 is about 255.3112436872.

It can be divided in two parts, 16642 and 165, that added together give a 5-th power (16807 = 7⁵).

The spelling of 16642165 in words is "sixteen million, six hundred forty-two thousand, one hundred sixty-five".