689705287 has 2 divisors, whose sum is σ = 689705288. Its totient is φ = 689705286.

The previous prime is 689705257. The next prime is 689705293. The reversal of 689705287 is 782507986.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689705287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689705257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344852643 + 344852644.

It is an arithmetic number, because the mean of its divisors is an integer number (344852644).

Almost surely, 2^689705287 is an apocalyptic number.

689705287 is a deficient number, since it is larger than the sum of its proper divisors (1).

689705287 is an equidigital number, since it uses as much as digits as its factorization.

689705287 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1693440, while the sum is 52.

The square root of 689705287 is about 26262.2407079061. The cubic root of 689705287 is about 883.5297652467.

The spelling of 689705287 in words is "six hundred eighty-nine million, seven hundred five thousand, two hundred eighty-seven".