172573321 has 2 divisors, whose sum is σ = 172573322. Its totient is φ = 172573320.

The previous prime is 172573267. The next prime is 172573327. The reversal of 172573321 is 123375271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152646025 + 19927296 = 12355^2 + 4464^2 .

It is a cyclic number.

It is not a de Polignac number, because 172573321 - 2²⁵ = 139018889 is a prime.

It is a super-2 number, since 2×172573321² = 59563102241938082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (172573327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86286660 + 86286661.

It is an arithmetic number, because the mean of its divisors is an integer number (86286661).

Almost surely, 2^172573321 is an apocalyptic number.

It is an amenable number.

172573321 is a deficient number, since it is larger than the sum of its proper divisors (1).

172573321 is an equidigital number, since it uses as much as digits as its factorization.

172573321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820, while the sum is 31.

The square root of 172573321 is about 13136.7165227845. The cubic root of 172573321 is about 556.7470000518.

The spelling of 172573321 in words is "one hundred seventy-two million, five hundred seventy-three thousand, three hundred twenty-one".