172438261 has 4 divisors (see below), whose sum is σ = 173160000. Its totient is φ = 171716524.

The previous prime is 172438249. The next prime is 172438267. The reversal of 172438261 is 162834271.

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 a cyclic number.

It is not a de Polignac number, because 172438261 - 2⁵ = 172438229 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 (172438267) 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, 360511 + ... + 360988.

It is an arithmetic number, because the mean of its divisors is an integer number (43290000).

Almost surely, 2^172438261 is an apocalyptic number.

It is an amenable number.

172438261 is a deficient number, since it is larger than the sum of its proper divisors (721739).

172438261 is an equidigital number, since it uses as much as digits as its factorization.

172438261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721738.

The product of its digits is 16128, while the sum is 34.

The square root of 172438261 is about 13131.5749626616. The cubic root of 172438261 is about 556.6017209820.

The spelling of 172438261 in words is "one hundred seventy-two million, four hundred thirty-eight thousand, two hundred sixty-one".