172338581 has 2 divisors, whose sum is σ = 172338582. Its totient is φ = 172338580.

The previous prime is 172338557. The next prime is 172338583. The reversal of 172338581 is 185833271.

It is a happy number.

172338581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144985681 + 27352900 = 12041^2 + 5230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172338581 is a prime.

It is a super-2 number, since 2×172338581² = 59401173002187122, which contains 22 as substring.

Together with 172338583, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172338583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86169290 + 86169291.

It is an arithmetic number, because the mean of its divisors is an integer number (86169291).

Almost surely, 2^172338581 is an apocalyptic number.

It is an amenable number.

172338581 is a deficient number, since it is larger than the sum of its proper divisors (1).

172338581 is an equidigital number, since it uses as much as digits as its factorization.

172338581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 38.

The square root of 172338581 is about 13127.7789819908. The cubic root of 172338581 is about 556.4944502148.

It can be divided in two parts, 1723 and 38581, that added together give a palindrome (40304).

The spelling of 172338581 in words is "one hundred seventy-two million, three hundred thirty-eight thousand, five hundred eighty-one".