809090 has 8 divisors (see below), whose sum is σ = 1456380. Its totient is φ = 323632.

The previous prime is 809087. The next prime is 809093. The reversal of 809090 is 90908.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (809087) and next prime (809093).

It can be written as a sum of positive squares in 2 ways, for example, as 790321 + 18769 = 889^2 + 137^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

809090 is a modest number, since divided by 9090 gives 80 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (809093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40445 + ... + 40464.

2⁸⁰⁹⁰⁹⁰ is an apocalyptic number.

809090 is a deficient number, since it is larger than the sum of its proper divisors (647290).

809090 is a wasteful number, since it uses less digits than its factorization.

809090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80916.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 809090 is about 899.4943023722. The cubic root of 809090 is about 93.1820536832.

Adding to 809090 its reverse (90908), we get a palindrome (899998).

The spelling of 809090 in words is "eight hundred nine thousand, ninety".