2161321005 has 16 divisors (see below), whose sum is σ = 3478106880. Its totient is φ = 1146040128.

The previous prime is 2161320983. The next prime is 2161321021. The reversal of 2161321005 is 5001231612.

It is not a de Polignac number, because 2161321005 - 2²⁴ = 2144543789 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 413845 + ... + 419034.

It is an arithmetic number, because the mean of its divisors is an integer number (217381680).

Almost surely, 2^2161321005 is an apocalyptic number.

It is an amenable number.

2161321005 is a deficient number, since it is larger than the sum of its proper divisors (1316785875).

2161321005 is a wasteful number, since it uses less digits than its factorization.

2161321005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833060.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 2161321005 is about 46490.0097332750. The cubic root of 2161321005 is about 1292.9242805940.

Adding to 2161321005 its reverse (5001231612), we get a palindrome (7162552617).

The spelling of 2161321005 in words is "two billion, one hundred sixty-one million, three hundred twenty-one thousand, five".