801609989 has 2 divisors, whose sum is σ = 801609990. Its totient is φ = 801609988.

The previous prime is 801609947. The next prime is 801610003. The reversal of 801609989 is 989906108.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 785849089 + 15760900 = 28033^2 + 3970^2 .

It is a cyclic number.

It is not a de Polignac number, because 801609989 - 2⁸ = 801609733 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (801609089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400804994 + 400804995.

It is an arithmetic number, because the mean of its divisors is an integer number (400804995).

Almost surely, 2^801609989 is an apocalyptic number.

It is an amenable number.

801609989 is a deficient number, since it is larger than the sum of its proper divisors (1).

801609989 is an equidigital number, since it uses as much as digits as its factorization.

801609989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 279936, while the sum is 50.

The square root of 801609989 is about 28312.7177960718. The cubic root of 801609989 is about 928.9400916826.

The spelling of 801609989 in words is "eight hundred one million, six hundred nine thousand, nine hundred eighty-nine".