685998751 has 2 divisors, whose sum is σ = 685998752. Its totient is φ = 685998750.

The previous prime is 685998707. The next prime is 685998763. The reversal of 685998751 is 157899586.

685998751 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685998751 - 2⁷ = 685998623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685998701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342999375 + 342999376.

It is an arithmetic number, because the mean of its divisors is an integer number (342999376).

Almost surely, 2^685998751 is an apocalyptic number.

685998751 is a deficient number, since it is larger than the sum of its proper divisors (1).

685998751 is an equidigital number, since it uses as much as digits as its factorization.

685998751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5443200, while the sum is 58.

The square root of 685998751 is about 26191.5778638859. The cubic root of 685998751 is about 881.9441996739.

The spelling of 685998751 in words is "six hundred eighty-five million, nine hundred ninety-eight thousand, seven hundred fifty-one".