2821806 has 48 divisors (see below), whose sum is σ = 6814080. Its totient is φ = 838080.

The previous prime is 2821771. The next prime is 2821807. The reversal of 2821806 is 6081282.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2821806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2821807) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7060 + ... + 7448.

It is an arithmetic number, because the mean of its divisors is an integer number (141960).

2^2821806 is an apocalyptic number.

2821806 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 2821806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3407040).

2821806 is an abundant number, since it is smaller than the sum of its proper divisors (3992274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2821806 is a wasteful number, since it uses less digits than its factorization.

2821806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 438 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 2821806 is about 1679.8232049832. The cubic root of 2821806 is about 141.3109179375.

The spelling of 2821806 in words is "two million, eight hundred twenty-one thousand, eight hundred six".