686439983 has 2 divisors, whose sum is σ = 686439984. Its totient is φ = 686439982.

The previous prime is 686439979. The next prime is 686440009. The reversal of 686439983 is 389934686.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 686439983 - 2² = 686439979 is a prime.

It is a super-2 number, since 2×686439983² = 942399700522080578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686439683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343219991 + 343219992.

It is an arithmetic number, because the mean of its divisors is an integer number (343219992).

Almost surely, 2^686439983 is an apocalyptic number.

686439983 is a deficient number, since it is larger than the sum of its proper divisors (1).

686439983 is an equidigital number, since it uses as much as digits as its factorization.

686439983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6718464, while the sum is 56.

The square root of 686439983 is about 26199.9996755725. Note that the first 3 decimals coincide. The cubic root of 686439983 is about 882.1332469575.

The spelling of 686439983 in words is "six hundred eighty-six million, four hundred thirty-nine thousand, nine hundred eighty-three".