2778889680 has 320 divisors, whose sum is σ = 11079052800. Its totient is φ = 634894848.

The previous prime is 2778889679. The next prime is 2778889723. The reversal of 2778889680 is 869888772.

2778889680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×2778889680² = 15444455707221004800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1223586 + ... + 1225854.

It is an arithmetic number, because the mean of its divisors is an integer number (34622040).

Almost surely, 2^2778889680 is an apocalyptic number.

2778889680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2778889680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5539526400).

2778889680 is an abundant number, since it is smaller than the sum of its proper divisors (8300163120).

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

2778889680 is an equidigital number, since it uses as much as digits as its factorization.

2778889680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2310 (or 2286 counting only the distinct ones).

The product of its (nonzero) digits is 21676032, while the sum is 63.

The square root of 2778889680 is about 52715.1750447630. The cubic root of 2778889680 is about 1405.9086467466.

The spelling of 2778889680 in words is "two billion, seven hundred seventy-eight million, eight hundred eighty-nine thousand, six hundred eighty".