2172155225 has 6 divisors (see below), whose sum is σ = 2693472510. Its totient is φ = 1737724160.

The previous prime is 2172155179. The next prime is 2172155231. The reversal of 2172155225 is 5225512712.

It can be written as a sum of positive squares in 3 ways, for example, as 1713481 + 2170441744 = 1309^2 + 46588^2 .

It is not a de Polignac number, because 2172155225 - 2²⁴ = 2155378009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2172155191 and 2172155200.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43443080 + ... + 43443129.

It is an arithmetic number, because the mean of its divisors is an integer number (448912085).

Almost surely, 2^2172155225 is an apocalyptic number.

2172155225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2172155225 is a deficient number, since it is larger than the sum of its proper divisors (521317285).

2172155225 is an equidigital number, since it uses as much as digits as its factorization.

2172155225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86886219 (or 86886214 counting only the distinct ones).

The product of its digits is 14000, while the sum is 32.

The square root of 2172155225 is about 46606.3860967572. The cubic root of 2172155225 is about 1295.0810610996.

Adding to 2172155225 its reverse (5225512712), we get a palindrome (7397667937).

The spelling of 2172155225 in words is "two billion, one hundred seventy-two million, one hundred fifty-five thousand, two hundred twenty-five".