172550221 has 4 divisors (see below), whose sum is σ = 182700252. Its totient is φ = 162400192.

The previous prime is 172550197. The next prime is 172550227. The reversal of 172550221 is 122055271.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 81252196 + 91298025 = 9014^2 + 9555^2 .

It is a cyclic number.

It is not a de Polignac number, because 172550221 - 2¹⁵ = 172517453 is a prime.

It is a super-3 number, since 3×172550221³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172550227) 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, 5074990 + ... + 5075023.

It is an arithmetic number, because the mean of its divisors is an integer number (45675063).

Almost surely, 2^172550221 is an apocalyptic number.

It is an amenable number.

172550221 is a deficient number, since it is larger than the sum of its proper divisors (10150031).

172550221 is a wasteful number, since it uses less digits than its factorization.

172550221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10150030.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 172550221 is about 13135.8372782248. The cubic root of 172550221 is about 556.7221576070.

The spelling of 172550221 in words is "one hundred seventy-two million, five hundred fifty thousand, two hundred twenty-one".