609989 has 2 divisors, whose sum is σ = 609990. Its totient is φ = 609988.

The previous prime is 609979. The next prime is 609991. The reversal of 609989 is 989906.

609989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 422500 + 187489 = 650^2 + 433^2 .

It is a cyclic number.

It is not a de Polignac number, because 609989 - 2¹² = 605893 is a prime.

Together with 609991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (609929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304994 + 304995.

It is an arithmetic number, because the mean of its divisors is an integer number (304995).

2⁶⁰⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

609989 is a deficient number, since it is larger than the sum of its proper divisors (1).

609989 is an equidigital number, since it uses as much as digits as its factorization.

609989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 609989 is about 781.0179255305. The cubic root of 609989 is about 84.8087510994.

The spelling of 609989 in words is "six hundred nine thousand, nine hundred eighty-nine".