2781221872 has 40 divisors (see below), whose sum is σ = 6330688560. Its totient is φ = 1166945280.

The previous prime is 2781221867. The next prime is 2781221899.

2781221872 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 605497 + ... + 610072.

It is an arithmetic number, because the mean of its divisors is an integer number (158267214).

Almost surely, 2^2781221872 is an apocalyptic number.

2781221872 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

2781221872 is an abundant number, since it is smaller than the sum of its proper divisors (3549466688).

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

2781221872 is a wasteful number, since it uses less digits than its factorization.

2781221872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215601 (or 1215595 counting only the distinct ones).

The product of its digits is 50176, while the sum is 40.

The square root of 2781221872 is about 52737.2910946325. The cubic root of 2781221872 is about 1406.3018412046.

The spelling of 2781221872 in words is "two billion, seven hundred eighty-one million, two hundred twenty-one thousand, eight hundred seventy-two".