2809813 has 2 divisors, whose sum is σ = 2809814. Its totient is φ = 2809812.

The previous prime is 2809787. The next prime is 2809823. The reversal of 2809813 is 3189082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2630884 + 178929 = 1622^2 + 423^2 .

It is a cyclic number.

It is not a de Polignac number, because 2809813 - 2¹³ = 2801621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2809823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1404906 + 1404907.

It is an arithmetic number, because the mean of its divisors is an integer number (1404907).

2^2809813 is an apocalyptic number.

It is an amenable number.

2809813 is a deficient number, since it is larger than the sum of its proper divisors (1).

2809813 is an equidigital number, since it uses as much as digits as its factorization.

2809813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 2809813 is about 1676.2496830723. The cubic root of 2809813 is about 141.1104377636.

The spelling of 2809813 in words is "two million, eight hundred nine thousand, eight hundred thirteen".