172505897 has 2 divisors, whose sum is σ = 172505898. Its totient is φ = 172505896.

The previous prime is 172505849. The next prime is 172505899. The reversal of 172505897 is 798505271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111915241 + 60590656 = 10579^2 + 7784^2 .

It is an emirp because it is prime and its reverse (798505271) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172505897 is a prime.

Together with 172505899, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (172505899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86252948 + 86252949.

It is an arithmetic number, because the mean of its divisors is an integer number (86252949).

Almost surely, 2^172505897 is an apocalyptic number.

It is an amenable number.

172505897 is a deficient number, since it is larger than the sum of its proper divisors (1).

172505897 is an equidigital number, since it uses as much as digits as its factorization.

172505897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 176400, while the sum is 44.

The square root of 172505897 is about 13134.1500295984. The cubic root of 172505897 is about 556.6744840158.

The spelling of 172505897 in words is "one hundred seventy-two million, five hundred five thousand, eight hundred ninety-seven".