172261 has 4 divisors (see below), whose sum is σ = 182412. Its totient is φ = 162112.

The previous prime is 172259. The next prime is 172279. The reversal of 172261 is 162271.

172261 = 54² + 55² + ... + 87².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 162271 = 263 ⋅617.

It can be written as a sum of positive squares in 2 ways, for example, as 136161 + 36100 = 369^2 + 190^2 .

It is not a de Polignac number, because 172261 - 2¹ = 172259 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 (172561) 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, 5050 + ... + 5083.

It is an arithmetic number, because the mean of its divisors is an integer number (45603).

2¹⁷²²⁶¹ is an apocalyptic number.

It is an amenable number.

172261 is a deficient number, since it is larger than the sum of its proper divisors (10151).

172261 is a wasteful number, since it uses less digits than its factorization.

172261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10150.

The product of its digits is 168, while the sum is 19.

The square root of 172261 is about 415.0433712276. The cubic root of 172261 is about 55.6410932688.

It can be divided in two parts, 17 and 2261, that added together give a triangular number (2278 = T₆₇).

The spelling of 172261 in words is "one hundred seventy-two thousand, two hundred sixty-one".