28012840 has 128 divisors (see below), whose sum is σ = 72576000. Its totient is φ = 9676800.

The previous prime is 28012793. The next prime is 28012841. The reversal of 28012840 is 4821082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28012841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 683220 + ... + 683260.

It is an arithmetic number, because the mean of its divisors is an integer number (567000).

Almost surely, 2^28012840 is an apocalyptic number.

28012840 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 28012840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36288000).

28012840 is an abundant number, since it is smaller than the sum of its proper divisors (44563160).

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

28012840 is a wasteful number, since it uses less digits than its factorization.

28012840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 127 counting only the distinct ones).

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

The square root of 28012840 is about 5292.7157490271. The cubic root of 28012840 is about 303.7053065257.

The spelling of 28012840 in words is "twenty-eight million, twelve thousand, eight hundred forty".