28273440 has 192 divisors, whose sum is σ = 100590336. Its totient is φ = 6623232.

The previous prime is 28273409. The next prime is 28273447. The reversal of 28273440 is 4437282.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 28273398 and 28273407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28273447) 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, 143422 + ... + 143618.

It is an arithmetic number, because the mean of its divisors is an integer number (523908).

Almost surely, 2^28273440 is an apocalyptic number.

28273440 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 28273440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50295168).

28273440 is an abundant number, since it is smaller than the sum of its proper divisors (72316896).

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

28273440 is a wasteful number, since it uses less digits than its factorization.

28273440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 30.

The square root of 28273440 is about 5317.2774988710. The cubic root of 28273440 is about 304.6441787980.

The spelling of 28273440 in words is "twenty-eight million, two hundred seventy-three thousand, four hundred forty".