2778894720 has 384 divisors, whose sum is σ = 11240873280. Its totient is φ = 619683840.

The previous prime is 2778894683. The next prime is 2778894721. The reversal of 2778894720 is 274988772.

2778894720 is a `hidden beast` number, since 27 + 78 + 89 + 472 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778894721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 67777900 + ... + 67777940.

Almost surely, 2^2778894720 is an apocalyptic number.

2778894720 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 2778894720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5620436640).

2778894720 is an abundant number, since it is smaller than the sum of its proper divisors (8461978560).

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

2778894720 is an frugal number, since it uses more digits than its factorization.

2778894720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 3161088, while the sum is 54.

The square root of 2778894720 is about 52715.2228488128. Note that the first 3 decimals coincide. The cubic root of 2778894720 is about 1405.9094966994.

The spelling of 2778894720 in words is "two billion, seven hundred seventy-eight million, eight hundred ninety-four thousand, seven hundred twenty".