172002521 has 2 divisors, whose sum is σ = 172002522. Its totient is φ = 172002520.

The previous prime is 172002517. The next prime is 172002547. The reversal of 172002521 is 125200271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96746896 + 75255625 = 9836^2 + 8675^2 .

It is a cyclic number.

It is not a de Polignac number, because 172002521 - 2² = 172002517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 172002493 and 172002502.

It is not a weakly prime, because it can be changed into another prime (172002511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86001260 + 86001261.

It is an arithmetic number, because the mean of its divisors is an integer number (86001261).

Almost surely, 2^172002521 is an apocalyptic number.

It is an amenable number.

172002521 is a deficient number, since it is larger than the sum of its proper divisors (1).

172002521 is an equidigital number, since it uses as much as digits as its factorization.

172002521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 172002521 is about 13114.9731604758. The cubic root of 172002521 is about 556.1324936993.

Adding to 172002521 its reverse (125200271), we get a palindrome (297202792).

The spelling of 172002521 in words is "one hundred seventy-two million, two thousand, five hundred twenty-one".