686864665919 has 2 divisors, whose sum is σ = 686864665920. Its totient is φ = 686864665918.

The previous prime is 686864665871. The next prime is 686864665931. The reversal of 686864665919 is 919566468686.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 686864665919 - 2³² = 682569698623 is a prime.

It is a super-2 number, since 2×686864665919² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686864065919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343432332959 + 343432332960.

It is an arithmetic number, because the mean of its divisors is an integer number (343432332960).

Almost surely, 2^686864665919 is an apocalyptic number.

686864665919 is a deficient number, since it is larger than the sum of its proper divisors (1).

686864665919 is an equidigital number, since it uses as much as digits as its factorization.

686864665919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 806215680, while the sum is 74.

The spelling of 686864665919 in words is "six hundred eighty-six billion, eight hundred sixty-four million, six hundred sixty-five thousand, nine hundred nineteen".