172721572 has 6 divisors (see below), whose sum is σ = 302262758. Its totient is φ = 86360784.

The previous prime is 172721551. The next prime is 172721573. The reversal of 172721572 is 275127271.

It can be written as a sum of positive squares in only one way, i.e., 161391616 + 11329956 = 12704^2 + 3366^2 .

It is not an unprimeable number, because it can be changed into a prime (172721573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21590193 + ... + 21590200.

Almost surely, 2^172721572 is an apocalyptic number.

It is an amenable number.

172721572 is a deficient number, since it is larger than the sum of its proper divisors (129541186).

172721572 is a wasteful number, since it uses less digits than its factorization.

172721572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43180397 (or 43180395 counting only the distinct ones).

The product of its digits is 13720, while the sum is 34.

The square root of 172721572 is about 13142.3579315129. The cubic root of 172721572 is about 556.9063809556.

The spelling of 172721572 in words is "one hundred seventy-two million, seven hundred twenty-one thousand, five hundred seventy-two".