2778861220 has 24 divisors (see below), whose sum is σ = 5848920000. Its totient is φ = 1109008992.

The previous prime is 2778861193. The next prime is 2778861233. The reversal of 2778861220 is 221688772.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149470 + ... + 167029.

It is an arithmetic number, because the mean of its divisors is an integer number (243705000).

Almost surely, 2^2778861220 is an apocalyptic number.

2778861220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2778861220 is an abundant number, since it is smaller than the sum of its proper divisors (3070058780).

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

2778861220 is a wasteful number, since it uses less digits than its factorization.

2778861220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316947 (or 316945 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 43.

The square root of 2778861220 is about 52714.9051028265. The cubic root of 2778861220 is about 1405.9038471922.

The spelling of 2778861220 in words is "two billion, seven hundred seventy-eight million, eight hundred sixty-one thousand, two hundred twenty".