831664891 has 2 divisors, whose sum is σ = 831664892. Its totient is φ = 831664890.

The previous prime is 831664783. The next prime is 831664901. The reversal of 831664891 is 198466138.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 831664891 - 2¹³ = 831656699 is a prime.

It is not a weakly prime, because it can be changed into another prime (831664091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415832445 + 415832446.

It is an arithmetic number, because the mean of its divisors is an integer number (415832446).

Almost surely, 2^831664891 is an apocalyptic number.

831664891 is a deficient number, since it is larger than the sum of its proper divisors (1).

831664891 is an equidigital number, since it uses as much as digits as its factorization.

831664891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 831664891 is about 28838.6007115463. The cubic root of 831664891 is about 940.4075835452.

The spelling of 831664891 in words is "eight hundred thirty-one million, six hundred sixty-four thousand, eight hundred ninety-one".