687569438791 has 2 divisors, whose sum is σ = 687569438792. Its totient is φ = 687569438790.

The previous prime is 687569438783. The next prime is 687569438849. The reversal of 687569438791 is 197834965786.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687569438791 - 2³ = 687569438783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687569430791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343784719395 + 343784719396.

It is an arithmetic number, because the mean of its divisors is an integer number (343784719396).

Almost surely, 2^687569438791 is an apocalyptic number.

687569438791 is a deficient number, since it is larger than the sum of its proper divisors (1).

687569438791 is an equidigital number, since it uses as much as digits as its factorization.

687569438791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 548674560, while the sum is 73.

The spelling of 687569438791 in words is "six hundred eighty-seven billion, five hundred sixty-nine million, four hundred thirty-eight thousand, seven hundred ninety-one".