685418879 has 2 divisors, whose sum is σ = 685418880. Its totient is φ = 685418878.

The previous prime is 685418831. The next prime is 685418887. The reversal of 685418879 is 978814586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685418879 - 2¹² = 685414783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685418819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342709439 + 342709440.

It is an arithmetic number, because the mean of its divisors is an integer number (342709440).

Almost surely, 2^685418879 is an apocalyptic number.

685418879 is a deficient number, since it is larger than the sum of its proper divisors (1).

685418879 is an equidigital number, since it uses as much as digits as its factorization.

685418879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3870720, while the sum is 56.

The square root of 685418879 is about 26180.5057055818. The cubic root of 685418879 is about 881.6956283207.

The spelling of 685418879 in words is "six hundred eighty-five million, four hundred eighteen thousand, eight hundred seventy-nine".