172500521 has 2 divisors, whose sum is σ = 172500522. Its totient is φ = 172500520.

The previous prime is 172500473. The next prime is 172500551. The reversal of 172500521 is 125005271.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123654400 + 48846121 = 11120^2 + 6989^2 .

It is an emirp because it is prime and its reverse (125005271) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172500521 is a prime.

It is not a weakly prime, because it can be changed into another prime (172500551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86250260 + 86250261.

It is an arithmetic number, because the mean of its divisors is an integer number (86250261).

Almost surely, 2^172500521 is an apocalyptic number.

It is an amenable number.

172500521 is a deficient number, since it is larger than the sum of its proper divisors (1).

172500521 is an equidigital number, since it uses as much as digits as its factorization.

172500521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 172500521 is about 13133.9453706797. The cubic root of 172500521 is about 556.6687011930.

Adding to 172500521 its reverse (125005271), we get a palindrome (297505792).

The spelling of 172500521 in words is "one hundred seventy-two million, five hundred thousand, five hundred twenty-one".