687857347139 has 2 divisors, whose sum is σ = 687857347140. Its totient is φ = 687857347138.

The previous prime is 687857347109. The next prime is 687857347141. The reversal of 687857347139 is 931743758786.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687857347139 is a prime.

Together with 687857347141, 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 (687857347109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343928673569 + 343928673570.

It is an arithmetic number, because the mean of its divisors is an integer number (343928673570).

Almost surely, 2^687857347139 is an apocalyptic number.

687857347139 is a deficient number, since it is larger than the sum of its proper divisors (1).

687857347139 is an equidigital number, since it uses as much as digits as its factorization.

687857347139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 213373440, while the sum is 68.

The spelling of 687857347139 in words is "six hundred eighty-seven billion, eight hundred fifty-seven million, three hundred forty-seven thousand, one hundred thirty-nine".