2172156105 has 32 divisors (see below), whose sum is σ = 3975245568. Its totient is φ = 992160000.

The previous prime is 2172156071. The next prime is 2172156109. The reversal of 2172156105 is 5016512712.

It is not a de Polignac number, because 2172156105 - 2⁸ = 2172155849 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2172156109) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 128655 + ... + 144555.

It is an arithmetic number, because the mean of its divisors is an integer number (124226424).

Almost surely, 2^2172156105 is an apocalyptic number.

It is an amenable number.

2172156105 is a deficient number, since it is larger than the sum of its proper divisors (1803089463).

2172156105 is a wasteful number, since it uses less digits than its factorization.

2172156105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17217.

The product of its (nonzero) digits is 4200, while the sum is 30.

The square root of 2172156105 is about 46606.3955375225. The cubic root of 2172156105 is about 1295.0812359906.

Adding to 2172156105 its reverse (5016512712), we get a palindrome (7188668817).

The spelling of 2172156105 in words is "two billion, one hundred seventy-two million, one hundred fifty-six thousand, one hundred five".