27728778464 has 48 divisors (see below), whose sum is σ = 55545361200. Its totient is φ = 13622267904.

The previous prime is 27728778437. The next prime is 27728778499. The reversal of 27728778464 is 46487782772.

It is a junction number, because it is equal to n+sod(n) for n = 27728778397 and 27728778406.

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, 6713552 + ... + 6717680.

It is an arithmetic number, because the mean of its divisors is an integer number (1157195025).

Almost surely, 2^27728778464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27728778464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27772680600).

27728778464 is an abundant number, since it is smaller than the sum of its proper divisors (27816582736).

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

27728778464 is a wasteful number, since it uses less digits than its factorization.

27728778464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7755 (or 7747 counting only the distinct ones).

The product of its digits is 59006976, while the sum is 62.

The spelling of 27728778464 in words is "twenty-seven billion, seven hundred twenty-eight million, seven hundred seventy-eight thousand, four hundred sixty-four".