816984989 has 2 divisors, whose sum is σ = 816984990. Its totient is φ = 816984988.

The previous prime is 816984953. The next prime is 816984991. The reversal of 816984989 is 989489618.

816984989 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., 799928089 + 17056900 = 28283^2 + 4130^2 .

It is a cyclic number.

It is not a de Polignac number, because 816984989 - 2⁸ = 816984733 is a prime.

Together with 816984991, 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 (816974989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408492494 + 408492495.

It is an arithmetic number, because the mean of its divisors is an integer number (408492495).

Almost surely, 2^816984989 is an apocalyptic number.

It is an amenable number.

816984989 is a deficient number, since it is larger than the sum of its proper divisors (1).

816984989 is an equidigital number, since it uses as much as digits as its factorization.

816984989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8957952, while the sum is 62.

The square root of 816984989 is about 28582.9492705004. The cubic root of 816984989 is about 934.8415905961.

The spelling of 816984989 in words is "eight hundred sixteen million, nine hundred eighty-four thousand, nine hundred eighty-nine".