686778863 has 2 divisors, whose sum is σ = 686778864. Its totient is φ = 686778862.

The previous prime is 686778853. The next prime is 686778871. The reversal of 686778863 is 368877686.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 686778863 - 2¹⁶ = 686713327 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686778803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343389431 + 343389432.

It is an arithmetic number, because the mean of its divisors is an integer number (343389432).

Almost surely, 2^686778863 is an apocalyptic number.

686778863 is a deficient number, since it is larger than the sum of its proper divisors (1).

686778863 is an equidigital number, since it uses as much as digits as its factorization.

686778863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16257024, while the sum is 59.

The square root of 686778863 is about 26206.4660532472. The cubic root of 686778863 is about 882.2783861990.

The spelling of 686778863 in words is "six hundred eighty-six million, seven hundred seventy-eight thousand, eight hundred sixty-three".