686353909 has 2 divisors, whose sum is σ = 686353910. Its totient is φ = 686353908.

The previous prime is 686353901. The next prime is 686353939. The reversal of 686353909 is 909353686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 373842225 + 312511684 = 19335^2 + 17678^2 .

It is a cyclic number.

It is not a de Polignac number, because 686353909 - 2³ = 686353901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686353901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343176954 + 343176955.

It is an arithmetic number, because the mean of its divisors is an integer number (343176955).

Almost surely, 2^686353909 is an apocalyptic number.

It is an amenable number.

686353909 is a deficient number, since it is larger than the sum of its proper divisors (1).

686353909 is an equidigital number, since it uses as much as digits as its factorization.

686353909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1049760, while the sum is 49.

The square root of 686353909 is about 26198.3569904679. The cubic root of 686353909 is about 882.0963746342.

The spelling of 686353909 in words is "six hundred eighty-six million, three hundred fifty-three thousand, nine hundred nine".