686843851 has 2 divisors, whose sum is σ = 686843852. Its totient is φ = 686843850.

The previous prime is 686843837. The next prime is 686843869. The reversal of 686843851 is 158348686.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686843851 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 686843795 and 686843804.

It is not a weakly prime, because it can be changed into another prime (686843881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343421925 + 343421926.

It is an arithmetic number, because the mean of its divisors is an integer number (343421926).

Almost surely, 2^686843851 is an apocalyptic number.

686843851 is a deficient number, since it is larger than the sum of its proper divisors (1).

686843851 is an equidigital number, since it uses as much as digits as its factorization.

686843851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1105920, while the sum is 49.

The square root of 686843851 is about 26207.7059469157. The cubic root of 686843851 is about 882.3062145158.

The spelling of 686843851 in words is "six hundred eighty-six million, eight hundred forty-three thousand, eight hundred fifty-one".