172221613 has 2 divisors, whose sum is σ = 172221614. Its totient is φ = 172221612.

The previous prime is 172221593. The next prime is 172221619. The reversal of 172221613 is 316122271.

It is a happy number.

172221613 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., 121484484 + 50737129 = 11022^2 + 7123^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172221613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172221619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86110806 + 86110807.

It is an arithmetic number, because the mean of its divisors is an integer number (86110807).

Almost surely, 2^172221613 is an apocalyptic number.

It is an amenable number.

172221613 is a deficient number, since it is larger than the sum of its proper divisors (1).

172221613 is an equidigital number, since it uses as much as digits as its factorization.

172221613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 172221613 is about 13123.3232452759. The cubic root of 172221613 is about 556.3685221836.

Adding to 172221613 its reverse (316122271), we get a palindrome (488343884).

The spelling of 172221613 in words is "one hundred seventy-two million, two hundred twenty-one thousand, six hundred thirteen".