686138923 has 2 divisors, whose sum is σ = 686138924. Its totient is φ = 686138922.

The previous prime is 686138911. The next prime is 686138951. The reversal of 686138923 is 329831686.

686138923 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 686138923 - 2²⁹ = 149268011 is a prime.

It is not a weakly prime, because it can be changed into another prime (686138993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343069461 + 343069462.

It is an arithmetic number, because the mean of its divisors is an integer number (343069462).

Almost surely, 2^686138923 is an apocalyptic number.

686138923 is a deficient number, since it is larger than the sum of its proper divisors (1).

686138923 is an equidigital number, since it uses as much as digits as its factorization.

686138923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 46.

The square root of 686138923 is about 26194.2536255569. The cubic root of 686138923 is about 882.0042656060.

The spelling of 686138923 in words is "six hundred eighty-six million, one hundred thirty-eight thousand, nine hundred twenty-three".