810500989 has 2 divisors, whose sum is σ = 810500990. Its totient is φ = 810500988.

The previous prime is 810500987. The next prime is 810501011. The reversal of 810500989 is 989005018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 641760889 + 168740100 = 25333^2 + 12990^2 .

It is a cyclic number.

It is not a de Polignac number, because 810500989 - 2¹ = 810500987 is a prime.

Together with 810500987, 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 (810500987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405250494 + 405250495.

It is an arithmetic number, because the mean of its divisors is an integer number (405250495).

Almost surely, 2^810500989 is an apocalyptic number.

It is an amenable number.

810500989 is a deficient number, since it is larger than the sum of its proper divisors (1).

810500989 is an equidigital number, since it uses as much as digits as its factorization.

810500989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 810500989 is about 28469.2990605670. The cubic root of 810500989 is about 932.3618960425.

The spelling of 810500989 in words is "eight hundred ten million, five hundred thousand, nine hundred eighty-nine".