691110859 has 2 divisors, whose sum is σ = 691110860. Its totient is φ = 691110858.

The previous prime is 691110857. The next prime is 691110887. The reversal of 691110859 is 958011196.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 691110859 - 2¹ = 691110857 is a prime.

Together with 691110857, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (691110851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345555429 + 345555430.

It is an arithmetic number, because the mean of its divisors is an integer number (345555430).

Almost surely, 2^691110859 is an apocalyptic number.

691110859 is a deficient number, since it is larger than the sum of its proper divisors (1).

691110859 is an equidigital number, since it uses as much as digits as its factorization.

691110859 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 40.

The square root of 691110859 is about 26288.9874091795. The cubic root of 691110859 is about 884.1295489827.

The spelling of 691110859 in words is "six hundred ninety-one million, one hundred ten thousand, eight hundred fifty-nine".