689299621 has 2 divisors, whose sum is σ = 689299622. Its totient is φ = 689299620.

The previous prime is 689299619. The next prime is 689299657. The reversal of 689299621 is 126992986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 512116900 + 177182721 = 22630^2 + 13311^2 .

It is a cyclic number.

It is not a de Polignac number, because 689299621 - 2¹ = 689299619 is a prime.

Together with 689299619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689299691) 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, 344649810 + 344649811.

It is an arithmetic number, because the mean of its divisors is an integer number (344649811).

Almost surely, 2^689299621 is an apocalyptic number.

It is an amenable number.

689299621 is a deficient number, since it is larger than the sum of its proper divisors (1).

689299621 is an equidigital number, since it uses as much as digits as its factorization.

689299621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 52.

The square root of 689299621 is about 26254.5162019794. The cubic root of 689299621 is about 883.3565085016.

The spelling of 689299621 in words is "six hundred eighty-nine million, two hundred ninety-nine thousand, six hundred twenty-one".