2809231 has 4 divisors (see below), whose sum is σ = 2812752. Its totient is φ = 2805712.

The previous prime is 2809223. The next prime is 2809241. The reversal of 2809231 is 1329082.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2809231 - 2³ = 2809223 is a prime.

It is a super-2 number, since 2×2809231² = 15783557622722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2809196 and 2809205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2809211) 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, 75 + ... + 2371.

It is an arithmetic number, because the mean of its divisors is an integer number (703188).

2^2809231 is an apocalyptic number.

2809231 is a deficient number, since it is larger than the sum of its proper divisors (3521).

2809231 is a wasteful number, since it uses less digits than its factorization.

2809231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3520.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 2809231 is about 1676.0760722593. The cubic root of 2809231 is about 141.1006942984.

The spelling of 2809231 in words is "two million, eight hundred nine thousand, two hundred thirty-one".