691498686089 has 2 divisors, whose sum is σ = 691498686090. Its totient is φ = 691498686088.

The previous prime is 691498686061. The next prime is 691498686143. The reversal of 691498686089 is 980686894196.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 350355080464 + 341143605625 = 591908^2 + 584075^2 .

It is a cyclic number.

It is not a de Polignac number, because 691498686089 - 2²⁰ = 691497637513 is a prime.

It is not a weakly prime, because it can be changed into another prime (691498686019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345749343044 + 345749343045.

It is an arithmetic number, because the mean of its divisors is an integer number (345749343045).

Almost surely, 2^691498686089 is an apocalyptic number.

It is an amenable number.

691498686089 is a deficient number, since it is larger than the sum of its proper divisors (1).

691498686089 is an equidigital number, since it uses as much as digits as its factorization.

691498686089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 322486272, while the sum is 74.

The spelling of 691498686089 in words is "six hundred ninety-one billion, four hundred ninety-eight million, six hundred eighty-six thousand, eighty-nine".