2165105321 has 4 divisors (see below), whose sum is σ = 2194764372. Its totient is φ = 2135446272.

The previous prime is 2165105291. The next prime is 2165105339. The reversal of 2165105321 is 1235015612.

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 1783879696 + 381225625 = 42236^2 + 19525^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2165105321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2165105351) 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, 14829416 + ... + 14829561.

It is an arithmetic number, because the mean of its divisors is an integer number (548691093).

Almost surely, 2^2165105321 is an apocalyptic number.

It is an amenable number.

2165105321 is a deficient number, since it is larger than the sum of its proper divisors (29659051).

2165105321 is an equidigital number, since it uses as much as digits as its factorization.

2165105321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29659050.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 2165105321 is about 46530.6922471609. The cubic root of 2165105321 is about 1293.6784460850.

The spelling of 2165105321 in words is "two billion, one hundred sixty-five million, one hundred five thousand, three hundred twenty-one".