2402809 has 4 divisors (see below), whose sum is σ = 2415204. Its totient is φ = 2390416.

The previous prime is 2402791. The next prime is 2402819. The reversal of 2402809 is 9082042.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9082042 = 2 ⋅4541021.

It can be written as a sum of positive squares in 2 ways, for example, as 2111209 + 291600 = 1453^2 + 540^2 .

It is a cyclic number.

It is not a de Polignac number, because 2402809 - 2⁹ = 2402297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2402819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5902 + ... + 6295.

It is an arithmetic number, because the mean of its divisors is an integer number (603801).

2^2402809 is an apocalyptic number.

It is an amenable number.

2402809 is a deficient number, since it is larger than the sum of its proper divisors (12395).

2402809 is a wasteful number, since it uses less digits than its factorization.

2402809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12394.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 2402809 is about 1550.0996742145. The cubic root of 2402809 is about 133.9388040165.

The spelling of 2402809 in words is "two million, four hundred two thousand, eight hundred nine".