2781978372 has 30 divisors (see below), whose sum is σ = 7272641838. Its totient is φ = 927326016.

The previous prime is 2781978341. The next prime is 2781978373. The reversal of 2781978372 is 2738791872.

It can be written as a sum of positive squares in only one way, i.e., 1940050116 + 841928256 = 44046^2 + 29016^2 .

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (2781978373) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4292853 + ... + 4293500.

Almost surely, 2^2781978372 is an apocalyptic number.

It is an amenable number.

2781978372 is an abundant number, since it is smaller than the sum of its proper divisors (4490663466).

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

2781978372 is a wasteful number, since it uses less digits than its factorization.

2781978372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8586369 (or 8586358 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 54.

The square root of 2781978372 is about 52744.4629511004. The cubic root of 2781978372 is about 1406.4293356355.

The spelling of 2781978372 in words is "two billion, seven hundred eighty-one million, nine hundred seventy-eight thousand, three hundred seventy-two".