28281400 has 48 divisors (see below), whose sum is σ = 75151440. Its totient is φ = 9696000.

The previous prime is 28281391. The next prime is 28281403. The reversal of 28281400 is 418282.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28281403) 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 11 ways as a sum of consecutive naturals, for example, 8701 + ... + 11500.

It is an arithmetic number, because the mean of its divisors is an integer number (1565655).

Almost surely, 2^28281400 is an apocalyptic number.

28281400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28281400 is an abundant number, since it is smaller than the sum of its proper divisors (46870040).

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

28281400 is a wasteful number, since it uses less digits than its factorization.

28281400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20224 (or 20215 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 28281400 is about 5318.0259495418. The cubic root of 28281400 is about 304.6727655816.

Adding to 28281400 its reverse (418282), we get a palindrome (28699682).

The spelling of 28281400 in words is "twenty-eight million, two hundred eighty-one thousand, four hundred".