2809121 has 6 divisors (see below), whose sum is σ = 3267810. Its totient is φ = 2407776.

The previous prime is 2809117. The next prime is 2809141. The reversal of 2809121 is 1219082.

2809121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1677025 + 1132096 = 1295^2 + 1064^2 .

It is not a de Polignac number, because 2809121 - 2² = 2809117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2809141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28616 + ... + 28713.

It is an arithmetic number, because the mean of its divisors is an integer number (544635).

2^2809121 is an apocalyptic number.

It is an amenable number.

2809121 is a deficient number, since it is larger than the sum of its proper divisors (458689).

2809121 is an equidigital number, since it uses as much as digits as its factorization.

2809121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57343 (or 57336 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 2809121 is about 1676.0432571983. The cubic root of 2809121 is about 141.0988525988.

It can be divided in two parts, 2809 and 121, that multiplied together give a square (339889 = 583²).

The spelling of 2809121 in words is "two million, eight hundred nine thousand, one hundred twenty-one".