1002809 has 2 divisors, whose sum is σ = 1002810. Its totient is φ = 1002808.

The previous prime is 1002797. The next prime is 1002817. The reversal of 1002809 is 9082001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1000000 + 2809 = 1000^2 + 53^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002809 - 2⁸ = 1002553 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1002899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501404 + 501405.

It is an arithmetic number, because the mean of its divisors is an integer number (501405).

2^1002809 is an apocalyptic number.

It is an amenable number.

1002809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002809 is an equidigital number, since it uses as much as digits as its factorization.

1002809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 1002809 is about 1001.4035150727. The cubic root of 1002809 is about 100.0935457979.

It can be divided in two parts, 100 and 2809, that multiplied together give a square (280900 = 530²).

The spelling of 1002809 in words is "one million, two thousand, eight hundred nine".