173172491 has 2 divisors, whose sum is σ = 173172492. Its totient is φ = 173172490.

The previous prime is 173172463. The next prime is 173172499. The reversal of 173172491 is 194271371.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-173172491 is a prime.

It is not a weakly prime, because it can be changed into another prime (173172499) 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, 86586245 + 86586246.

It is an arithmetic number, because the mean of its divisors is an integer number (86586246).

Almost surely, 2^173172491 is an apocalyptic number.

173172491 is a deficient number, since it is larger than the sum of its proper divisors (1).

173172491 is an equidigital number, since it uses as much as digits as its factorization.

173172491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10584, while the sum is 35.

The square root of 173172491 is about 13159.5019282646. The cubic root of 173172491 is about 557.3905927262.

The spelling of 173172491 in words is "one hundred seventy-three million, one hundred seventy-two thousand, four hundred ninety-one".