686392891 has 2 divisors, whose sum is σ = 686392892. Its totient is φ = 686392890.

The previous prime is 686392873. The next prime is 686392991. The reversal of 686392891 is 198293686.

It is a happy number.

686392891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 686392891 - 2⁹ = 686392379 is a prime.

It is a super-2 number, since 2×686392891² = 942270401630675762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (686392871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343196445 + 343196446.

It is an arithmetic number, because the mean of its divisors is an integer number (343196446).

Almost surely, 2^686392891 is an apocalyptic number.

686392891 is a deficient number, since it is larger than the sum of its proper divisors (1).

686392891 is an equidigital number, since it uses as much as digits as its factorization.

686392891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1119744, while the sum is 52.

The square root of 686392891 is about 26199.1009578573. The cubic root of 686392891 is about 882.1130740995.

The spelling of 686392891 in words is "six hundred eighty-six million, three hundred ninety-two thousand, eight hundred ninety-one".