172197128 has 16 divisors (see below), whose sum is σ = 334003500. Its totient is φ = 83129536.

The previous prime is 172197121. The next prime is 172197161. The reversal of 172197128 is 821791271.

It can be written as a sum of positive squares in 2 ways, for example, as 163891204 + 8305924 = 12802^2 + 2882^2 .

It is a junction number, because it is equal to n+sod(n) for n = 172197091 and 172197100.

It is not an unprimeable number, because it can be changed into a prime (172197121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 370883 + ... + 371346.

Almost surely, 2^172197128 is an apocalyptic number.

It is an amenable number.

172197128 is a deficient number, since it is larger than the sum of its proper divisors (161806372).

172197128 is a wasteful number, since it uses less digits than its factorization.

172197128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742264 (or 742260 counting only the distinct ones).

The product of its digits is 14112, while the sum is 38.

The square root of 172197128 is about 13122.3903310334. The cubic root of 172197128 is about 556.3421543569.

The spelling of 172197128 in words is "one hundred seventy-two million, one hundred ninety-seven thousand, one hundred twenty-eight".