28322778 has 64 divisors (see below), whose sum is σ = 64880640. Its totient is φ = 8164800.

The previous prime is 28322771. The next prime is 28322783. The reversal of 28322778 is 87722382.

It is not an unprimeable number, because it can be changed into a prime (28322771) 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, 222951 + ... + 223077.

It is an arithmetic number, because the mean of its divisors is an integer number (1013760).

Almost surely, 2^28322778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28322778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32440320).

28322778 is an abundant number, since it is smaller than the sum of its proper divisors (36557862).

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

28322778 is a wasteful number, since it uses less digits than its factorization.

28322778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283.

The product of its digits is 75264, while the sum is 39.

The square root of 28322778 is about 5321.9148809428. The cubic root of 28322778 is about 304.8212802290.

It can be divided in two parts, 28 and 322778, that added together give a triangular number (322806 = T₈₀₃).

The spelling of 28322778 in words is "twenty-eight million, three hundred twenty-two thousand, seven hundred seventy-eight".