12778449640 has 64 divisors (see below), whose sum is σ = 31402728000. Its totient is φ = 4641162240.

The previous prime is 12778449637. The next prime is 12778449661. The reversal of 12778449640 is 4694487721.

It is a super-2 number, since 2×12778449640² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 361056 + ... + 394864.

It is an arithmetic number, because the mean of its divisors is an integer number (490667625).

Almost surely, 2^12778449640 is an apocalyptic number.

12778449640 is a gapful number since it is divisible by the number (10) 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 12778449640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15701364000).

12778449640 is an abundant number, since it is smaller than the sum of its proper divisors (18624278360).

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

12778449640 is a wasteful number, since it uses less digits than its factorization.

12778449640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34690 (or 34686 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 52.

The spelling of 12778449640 in words is "twelve billion, seven hundred seventy-eight million, four hundred forty-nine thousand, six hundred forty".