2172256605 has 48 divisors (see below), whose sum is σ = 3982530240. Its totient is φ = 1092268800.

The previous prime is 2172256441. The next prime is 2172256607. The reversal of 2172256605 is 5066522712.

2172256605 is a `hidden beast` number, since 21 + 7 + 2 + 25 + 6 + 605 = 666.

It is not a de Polignac number, because 2172256605 - 2⁸ = 2172256349 is a prime.

It is a super-2 number, since 2×2172256605² = 9437397515932252050, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2172256605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172256607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 174385 + ... + 186425.

It is an arithmetic number, because the mean of its divisors is an integer number (82969380).

Almost surely, 2^2172256605 is an apocalyptic number.

It is an amenable number.

2172256605 is a deficient number, since it is larger than the sum of its proper divisors (1810273635).

2172256605 is a wasteful number, since it uses less digits than its factorization.

2172256605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12282 (or 12279 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 2172256605 is about 46607.4737032592. The cubic root of 2172256605 is about 1295.1012090267.

The spelling of 2172256605 in words is "two billion, one hundred seventy-two million, two hundred fifty-six thousand, six hundred five".