686635667 has 2 divisors, whose sum is σ = 686635668. Its totient is φ = 686635666.

The previous prime is 686635601. The next prime is 686635669. The reversal of 686635667 is 766536686.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 686635667 - 2¹⁰ = 686634643 is a prime.

Together with 686635669, 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 (686635669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343317833 + 343317834.

It is an arithmetic number, because the mean of its divisors is an integer number (343317834).

Almost surely, 2^686635667 is an apocalyptic number.

686635667 is a deficient number, since it is larger than the sum of its proper divisors (1).

686635667 is an equidigital number, since it uses as much as digits as its factorization.

686635667 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6531840, while the sum is 53.

The square root of 686635667 is about 26203.7338369935. The cubic root of 686635667 is about 882.2170624725.

The spelling of 686635667 in words is "six hundred eighty-six million, six hundred thirty-five thousand, six hundred sixty-seven".