685705379 has 2 divisors, whose sum is σ = 685705380. Its totient is φ = 685705378.

The previous prime is 685705351. The next prime is 685705381. The reversal of 685705379 is 973507586.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685705379 - 2⁸ = 685705123 is a prime.

Together with 685705381, 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 (685705309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342852689 + 342852690.

It is an arithmetic number, because the mean of its divisors is an integer number (342852690).

Almost surely, 2^685705379 is an apocalyptic number.

685705379 is a deficient number, since it is larger than the sum of its proper divisors (1).

685705379 is an equidigital number, since it uses as much as digits as its factorization.

685705379 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1587600, while the sum is 50.

The square root of 685705379 is about 26185.9767623818. The cubic root of 685705379 is about 881.8184586159.

The spelling of 685705379 in words is "six hundred eighty-five million, seven hundred five thousand, three hundred seventy-nine".