28126440 has 80 divisors (see below), whose sum is σ = 94546980. Its totient is φ = 7499520.

The previous prime is 28126409. The next prime is 28126453. The reversal of 28126440 is 4462182.

28126440 is a `hidden beast` number, since 2 + 8 + 12 + 644 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 27815076 + 311364 = 5274^2 + 558^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 1101 + ... + 7580.

Almost surely, 2^28126440 is an apocalyptic number.

28126440 is a gapful number since it is divisible by the number (20) 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 28126440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47273490).

28126440 is an abundant number, since it is smaller than the sum of its proper divisors (66420540).

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

28126440 is a wasteful number, since it uses less digits than its factorization.

28126440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8704 (or 8691 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28126440 is about 5303.4366216634. The cubic root of 28126440 is about 304.1152898358.

The spelling of 28126440 in words is "twenty-eight million, one hundred twenty-six thousand, four hundred forty".