172170198225 has 18 divisors (see below), whose sum is σ = 308375955446. Its totient is φ = 91824105600.

The previous prime is 172170198169. The next prime is 172170198259. The reversal of 172170198225 is 522891071271.

172170198225 is a `hidden beast` number, since 1 + 72 + 170 + 198 + 225 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 567964224 + 171602234001 = 23832^2 + 414249^2 .

It is a de Polignac number, because none of the positive numbers 2^k-172170198225 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 382600216 + ... + 382600665.

Almost surely, 2^172170198225 is an apocalyptic number.

172170198225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

172170198225 is a deficient number, since it is larger than the sum of its proper divisors (136205757221).

172170198225 is a wasteful number, since it uses less digits than its factorization.

172170198225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765200897 (or 765200889 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The spelling of 172170198225 in words is "one hundred seventy-two billion, one hundred seventy million, one hundred ninety-eight thousand, two hundred twenty-five".