172328621 has 2 divisors, whose sum is σ = 172328622. Its totient is φ = 172328620.

The previous prime is 172328593. The next prime is 172328633. The reversal of 172328621 is 126823271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115326121 + 57002500 = 10739^2 + 7550^2 .

It is a cyclic number.

It is not a de Polignac number, because 172328621 - 2¹⁴ = 172312237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172328641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86164310 + 86164311.

It is an arithmetic number, because the mean of its divisors is an integer number (86164311).

Almost surely, 2^172328621 is an apocalyptic number.

It is an amenable number.

172328621 is a deficient number, since it is larger than the sum of its proper divisors (1).

172328621 is an equidigital number, since it uses as much as digits as its factorization.

172328621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 32.

The square root of 172328621 is about 13127.3996282584. The cubic root of 172328621 is about 556.4837294745.

The spelling of 172328621 in words is "one hundred seventy-two million, three hundred twenty-eight thousand, six hundred twenty-one".