2821978836 has 72 divisors (see below), whose sum is σ = 7482471360. Its totient is φ = 895048704.

The previous prime is 2821978787. The next prime is 2821978837. The reversal of 2821978836 is 6388791282.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2821978837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 150975 + ... + 168633.

Almost surely, 2^2821978836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2821978836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3741235680).

2821978836 is an abundant number, since it is smaller than the sum of its proper divisors (4660492524).

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

2821978836 is a wasteful number, since it uses less digits than its factorization.

2821978836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17885 (or 17880 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 54.

The square root of 2821978836 is about 53122.3007408376. The cubic root of 2821978836 is about 1413.1380298293.

The spelling of 2821978836 in words is "two billion, eight hundred twenty-one million, nine hundred seventy-eight thousand, eight hundred thirty-six".