2781921228 has 12 divisors (see below), whose sum is σ = 6491149560. Its totient is φ = 927307072.

The previous prime is 2781921227. The next prime is 2781921239. The reversal of 2781921228 is 8221291872.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 2781921228.

It is not an unprimeable number, because it can be changed into a prime (2781921221) 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, 115913373 + ... + 115913396.

It is an arithmetic number, because the mean of its divisors is an integer number (540929130).

Almost surely, 2^2781921228 is an apocalyptic number.

It is an amenable number.

2781921228 is an abundant number, since it is smaller than the sum of its proper divisors (3709228332).

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

2781921228 is a wasteful number, since it uses less digits than its factorization.

2781921228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231826776 (or 231826774 counting only the distinct ones).

The product of its digits is 64512, while the sum is 42.

The square root of 2781921228 is about 52743.9212421678. The cubic root of 2781921228 is about 1406.4197058520.

The spelling of 2781921228 in words is "two billion, seven hundred eighty-one million, nine hundred twenty-one thousand, two hundred twenty-eight".