2778509916 has 288 divisors, whose sum is σ = 9295104000. Its totient is φ = 693463680.

The previous prime is 2778509893. The next prime is 2778509927. The reversal of 2778509916 is 6199058772.

2778509916 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3049501 + ... + 3050411.

Almost surely, 2^2778509916 is an apocalyptic number.

2778509916 is a gapful number since it is divisible by the number (26) 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 2778509916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4647552000).

2778509916 is an abundant number, since it is smaller than the sum of its proper divisors (6516594084).

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

2778509916 is a wasteful number, since it uses less digits than its factorization.

2778509916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974 (or 955 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 54.

The square root of 2778509916 is about 52711.5728848988. The cubic root of 2778509916 is about 1405.8445998458.

The spelling of 2778509916 in words is "two billion, seven hundred seventy-eight million, five hundred nine thousand, nine hundred sixteen".