817072891 has 2 divisors, whose sum is σ = 817072892. Its totient is φ = 817072890.

The previous prime is 817072849. The next prime is 817072909. The reversal of 817072891 is 198270718.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 817072891 - 2⁹ = 817072379 is a prime.

It is not a weakly prime, because it can be changed into another prime (817072801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408536445 + 408536446.

It is an arithmetic number, because the mean of its divisors is an integer number (408536446).

Almost surely, 2^817072891 is an apocalyptic number.

817072891 is a deficient number, since it is larger than the sum of its proper divisors (1).

817072891 is an equidigital number, since it uses as much as digits as its factorization.

817072891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 43.

The square root of 817072891 is about 28584.4868941179. The cubic root of 817072891 is about 934.8751169153.

The spelling of 817072891 in words is "eight hundred seventeen million, seventy-two thousand, eight hundred ninety-one".