685390829 has 2 divisors, whose sum is σ = 685390830. Its totient is φ = 685390828.

The previous prime is 685390799. The next prime is 685390841. The reversal of 685390829 is 928093586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 573602500 + 111788329 = 23950^2 + 10573^2 .

It is a cyclic number.

It is not a de Polignac number, because 685390829 - 2¹⁶ = 685325293 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685390429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342695414 + 342695415.

It is an arithmetic number, because the mean of its divisors is an integer number (342695415).

Almost surely, 2^685390829 is an apocalyptic number.

It is an amenable number.

685390829 is a deficient number, since it is larger than the sum of its proper divisors (1).

685390829 is an equidigital number, since it uses as much as digits as its factorization.

685390829 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 50.

The square root of 685390829 is about 26179.9699961631. The cubic root of 685390829 is about 881.6836006879.

The spelling of 685390829 in words is "six hundred eighty-five million, three hundred ninety thousand, eight hundred twenty-nine".