831240689 has 2 divisors, whose sum is σ = 831240690. Its totient is φ = 831240688.

The previous prime is 831240667. The next prime is 831240691. The reversal of 831240689 is 986042138.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624600064 + 206640625 = 24992^2 + 14375^2 .

It is a cyclic number.

It is not a de Polignac number, because 831240689 - 2²⁰ = 830192113 is a prime.

It is a super-2 number, since 2×831240689² = 1381922166098389442, which contains 22 as substring.

Together with 831240691, 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 (831240629) 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, 415620344 + 415620345.

It is an arithmetic number, because the mean of its divisors is an integer number (415620345).

Almost surely, 2^831240689 is an apocalyptic number.

It is an amenable number.

831240689 is a deficient number, since it is larger than the sum of its proper divisors (1).

831240689 is an equidigital number, since it uses as much as digits as its factorization.

831240689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 831240689 is about 28831.2450130063. The cubic root of 831240689 is about 940.2476671227.

The spelling of 831240689 in words is "eight hundred thirty-one million, two hundred forty thousand, six hundred eighty-nine".