810989 has 2 divisors, whose sum is σ = 810990. Its totient is φ = 810988.

The previous prime is 810973. The next prime is 811037. The reversal of 810989 is 989018.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 592900 + 218089 = 770^2 + 467^2 .

It is a cyclic number.

It is not a de Polignac number, because 810989 - 2⁴ = 810973 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (810949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405494 + 405495.

It is an arithmetic number, because the mean of its divisors is an integer number (405495).

2⁸¹⁰⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

810989 is a deficient number, since it is larger than the sum of its proper divisors (1).

810989 is an equidigital number, since it uses as much as digits as its factorization.

810989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 35.

The square root of 810989 is about 900.5492768305. The cubic root of 810989 is about 93.2548986734.

The spelling of 810989 in words is "eight hundred ten thousand, nine hundred eighty-nine".