691264589 has 2 divisors, whose sum is σ = 691264590. Its totient is φ = 691264588.

The previous prime is 691264559. The next prime is 691264597. The reversal of 691264589 is 985462196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 691164100 + 100489 = 26290^2 + 317^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691264589 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691264559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345632294 + 345632295.

It is an arithmetic number, because the mean of its divisors is an integer number (345632295).

Almost surely, 2^691264589 is an apocalyptic number.

It is an amenable number.

691264589 is a deficient number, since it is larger than the sum of its proper divisors (1).

691264589 is an equidigital number, since it uses as much as digits as its factorization.

691264589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 50.

The square root of 691264589 is about 26291.9110944792. The cubic root of 691264589 is about 884.1950990833.

The spelling of 691264589 in words is "six hundred ninety-one million, two hundred sixty-four thousand, five hundred eighty-nine".