172297728 has 120 divisors (see below), whose sum is σ = 502702200. Its totient is φ = 56807424.

The previous prime is 172297693. The next prime is 172297751. The reversal of 172297728 is 827792271.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 640378 + ... + 640646.

It is an arithmetic number, because the mean of its divisors is an integer number (4189185).

Almost surely, 2^172297728 is an apocalyptic number.

172297728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172297728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (251351100).

172297728 is an abundant number, since it is smaller than the sum of its proper divisors (330404472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

172297728 is a wasteful number, since it uses less digits than its factorization.

172297728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 413 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The square root of 172297728 is about 13126.2229144564. Note that the first 3 decimals coincide. The cubic root of 172297728 is about 556.4504742533.

The spelling of 172297728 in words is "one hundred seventy-two million, two hundred ninety-seven thousand, seven hundred twenty-eight".