2858821 has 4 divisors (see below), whose sum is σ = 3267232. Its totient is φ = 2450412.

The previous prime is 2858819. The next prime is 2858827. The reversal of 2858821 is 1288582.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1288582 = 2 ⋅644291.

It is a cyclic number.

It is not a de Polignac number, because 2858821 - 2¹ = 2858819 is a prime.

It is a Duffinian number.

2858821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2858827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 204195 + ... + 204208.

It is an arithmetic number, because the mean of its divisors is an integer number (816808).

2^2858821 is an apocalyptic number.

It is an amenable number.

2858821 is a deficient number, since it is larger than the sum of its proper divisors (408411).

2858821 is an equidigital number, since it uses as much as digits as its factorization.

2858821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408410.

The product of its digits is 10240, while the sum is 34.

The square root of 2858821 is about 1690.8048379396. The cubic root of 2858821 is about 141.9261170899.

The spelling of 2858821 in words is "two million, eight hundred fifty-eight thousand, eight hundred twenty-one".