28006663440 has 320 divisors, whose sum is σ = 102493440000. Its totient is φ = 6322853376.

The previous prime is 28006663417. The next prime is 28006663441. The reversal of 28006663440 is 4436660082.

It is not an unprimeable number, because it can be changed into a prime (28006663441) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6830511 + ... + 6834609.

It is an arithmetic number, because the mean of its divisors is an integer number (320292000).

Almost surely, 2^28006663440 is an apocalyptic number.

28006663440 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 28006663440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51246720000).

28006663440 is an abundant number, since it is smaller than the sum of its proper divisors (74486776560).

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

28006663440 is a wasteful number, since it uses less digits than its factorization.

28006663440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4219 (or 4199 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 39.

The spelling of 28006663440 in words is "twenty-eight billion, six million, six hundred sixty-three thousand, four hundred forty".