27728778 has 64 divisors (see below), whose sum is σ = 70668288. Its totient is φ = 7043520.

The previous prime is 27728773. The next prime is 27728797. The reversal of 27728778 is 87782772.

It is not an unprimeable number, because it can be changed into a prime (27728773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21076 + ... + 22352.

It is an arithmetic number, because the mean of its divisors is an integer number (1104192).

Almost surely, 2^27728778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27728778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35334144).

27728778 is an abundant number, since it is smaller than the sum of its proper divisors (42939510).

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

27728778 is a wasteful number, since it uses less digits than its factorization.

27728778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347.

The product of its digits is 614656, while the sum is 48.

The square root of 27728778 is about 5265.8121880675. The cubic root of 27728778 is about 302.6752503167.

The spelling of 27728778 in words is "twenty-seven million, seven hundred twenty-eight thousand, seven hundred seventy-eight".