686693659 has 2 divisors, whose sum is σ = 686693660. Its totient is φ = 686693658.

The previous prime is 686693629. The next prime is 686693663. The reversal of 686693659 is 956396686.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686693659 is a prime.

It is not a weakly prime, because it can be changed into another prime (686693629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343346829 + 343346830.

It is an arithmetic number, because the mean of its divisors is an integer number (343346830).

Almost surely, 2^686693659 is an apocalyptic number.

686693659 is a deficient number, since it is larger than the sum of its proper divisors (1).

686693659 is an equidigital number, since it uses as much as digits as its factorization.

686693659 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12597120, while the sum is 58.

The square root of 686693659 is about 26204.8403734883. The cubic root of 686693659 is about 882.2418985896.

The spelling of 686693659 in words is "six hundred eighty-six million, six hundred ninety-three thousand, six hundred fifty-nine".