172726221 has 4 divisors (see below), whose sum is σ = 230301632. Its totient is φ = 115150812.

The previous prime is 172726199. The next prime is 172726241. The reversal of 172726221 is 122627271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 172726221 - 2⁵ = 172726189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172726241) 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, 28787701 + ... + 28787706.

It is an arithmetic number, because the mean of its divisors is an integer number (57575408).

Almost surely, 2^172726221 is an apocalyptic number.

It is an amenable number.

172726221 is a deficient number, since it is larger than the sum of its proper divisors (57575411).

172726221 is an equidigital number, since it uses as much as digits as its factorization.

172726221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57575410.

The product of its digits is 4704, while the sum is 30.

The square root of 172726221 is about 13142.5348011713. The cubic root of 172726221 is about 556.9113775030.

The spelling of 172726221 in words is "one hundred seventy-two million, seven hundred twenty-six thousand, two hundred twenty-one".