28043400 has 192 divisors, whose sum is σ = 108564480. Its totient is φ = 5817600.

The previous prime is 28043381. The next prime is 28043401. The reversal of 28043400 is 434082.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28043401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45897 + ... + 46503.

It is an arithmetic number, because the mean of its divisors is an integer number (565440).

Almost surely, 2^28043400 is an apocalyptic number.

28043400 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 28043400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54282240).

28043400 is an abundant number, since it is smaller than the sum of its proper divisors (80521080).

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

28043400 is a wasteful number, since it uses less digits than its factorization.

28043400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 28043400 is about 5295.6019487873. The cubic root of 28043400 is about 303.8157066275.

Adding to 28043400 its reverse (434082), we get a palindrome (28477482).

The spelling of 28043400 in words is "twenty-eight million, forty-three thousand, four hundred".