172521373 has 2 divisors, whose sum is σ = 172521374. Its totient is φ = 172521372.

The previous prime is 172521353. The next prime is 172521383. The reversal of 172521373 is 373125271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96098809 + 76422564 = 9803^2 + 8742^2 .

It is an emirp because it is prime and its reverse (373125271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172521373 - 2¹³ = 172513181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172521313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86260686 + 86260687.

It is an arithmetic number, because the mean of its divisors is an integer number (86260687).

Almost surely, 2^172521373 is an apocalyptic number.

It is an amenable number.

172521373 is a deficient number, since it is larger than the sum of its proper divisors (1).

172521373 is an equidigital number, since it uses as much as digits as its factorization.

172521373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8820, while the sum is 31.

The square root of 172521373 is about 13134.7391675663. The cubic root of 172521373 is about 556.6911304742.

The spelling of 172521373 in words is "one hundred seventy-two million, five hundred twenty-one thousand, three hundred seventy-three".