28197421056 has 512 divisors, whose sum is σ = 99403488000. Its totient is φ = 7729053696.

The previous prime is 28197421051. The next prime is 28197421079. The reversal of 28197421056 is 65012479182.

It is a tau number, because it is divible by the number of its divisors (512).

It is not an unprimeable number, because it can be changed into a prime (28197421051) 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, 179601330 + ... + 179601486.

Almost surely, 2^28197421056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28197421056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49701744000).

28197421056 is an abundant number, since it is smaller than the sum of its proper divisors (71206066944).

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

28197421056 is an equidigital number, since it uses as much as digits as its factorization.

28197421056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 28197421056 in words is "twenty-eight billion, one hundred ninety-seven million, four hundred twenty-one thousand, fifty-six".