687412139 has 2 divisors, whose sum is σ = 687412140. Its totient is φ = 687412138.

The previous prime is 687412091. The next prime is 687412157. The reversal of 687412139 is 931214786.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687412139 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 687412096 and 687412105.

It is not a weakly prime, because it can be changed into another prime (687412189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343706069 + 343706070.

It is an arithmetic number, because the mean of its divisors is an integer number (343706070).

Almost surely, 2^687412139 is an apocalyptic number.

687412139 is a deficient number, since it is larger than the sum of its proper divisors (1).

687412139 is an equidigital number, since it uses as much as digits as its factorization.

687412139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 687412139 is about 26218.5457071898. The cubic root of 687412139 is about 882.5494846619.

The spelling of 687412139 in words is "six hundred eighty-seven million, four hundred twelve thousand, one hundred thirty-nine".