691269889 has 2 divisors, whose sum is σ = 691269890. Its totient is φ = 691269888.

The previous prime is 691269871. The next prime is 691269949. The reversal of 691269889 is 988962196.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 691269264 + 625 = 26292^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 691269889 - 2⁹ = 691269377 is a prime.

It is not a weakly prime, because it can be changed into another prime (691269809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345634944 + 345634945.

It is an arithmetic number, because the mean of its divisors is an integer number (345634945).

Almost surely, 2^691269889 is an apocalyptic number.

It is an amenable number.

691269889 is a deficient number, since it is larger than the sum of its proper divisors (1).

691269889 is an equidigital number, since it uses as much as digits as its factorization.

691269889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 58.

The square root of 691269889 is about 26292.0118857420. The cubic root of 691269889 is about 884.1973588172.

The spelling of 691269889 in words is "six hundred ninety-one million, two hundred sixty-nine thousand, eight hundred eighty-nine".