28012400 has 60 divisors (see below), whose sum is σ = 72490152. Its totient is φ = 10341120.

The previous prime is 28012381. The next prime is 28012409. The reversal of 28012400 is 421082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28012409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2507 + ... + 7893.

Almost surely, 2^28012400 is an apocalyptic number.

28012400 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 28012400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36245076).

28012400 is an abundant number, since it is smaller than the sum of its proper divisors (44477752).

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

28012400 is a wasteful number, since it uses less digits than its factorization.

28012400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5418 (or 5407 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 28012400 is about 5292.6741823014. The cubic root of 28012400 is about 303.7037164093.

Adding to 28012400 its reverse (421082), we get a palindrome (28433482).

The spelling of 28012400 in words is "twenty-eight million, twelve thousand, four hundred".