2778787640 has 32 divisors (see below), whose sum is σ = 6259086000. Its totient is φ = 1110303744.

The previous prime is 2778787631. The next prime is 2778787673. The reversal of 2778787640 is 467878772.

2778787640 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 7 ways as a sum of consecutive naturals, for example, 230 + ... + 74549.

Almost surely, 2^2778787640 is an apocalyptic number.

2778787640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2778787640 is an abundant number, since it is smaller than the sum of its proper divisors (3480298360).

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

2778787640 is a wasteful number, since it uses less digits than its factorization.

2778787640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75719 (or 75715 counting only the distinct ones).

The product of its (nonzero) digits is 7375872, while the sum is 56.

The square root of 2778787640 is about 52714.2071931277. The cubic root of 2778787640 is about 1405.8914383539.

The spelling of 2778787640 in words is "two billion, seven hundred seventy-eight million, seven hundred eighty-seven thousand, six hundred forty".