28001438208 has 320 divisors, whose sum is σ = 88905738240. Its totient is φ = 8778792960.

The previous prime is 28001438203. The next prime is 28001438249. The reversal of 28001438208 is 80283410082.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28001438203) 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, 19034913 + ... + 19036383.

It is an arithmetic number, because the mean of its divisors is an integer number (277830432).

Almost surely, 2^28001438208 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 28001438208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44452869120).

28001438208 is an abundant number, since it is smaller than the sum of its proper divisors (60904300032).

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

28001438208 is an frugal number, since it uses more digits than its factorization.

28001438208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1527 (or 1493 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The spelling of 28001438208 in words is "twenty-eight billion, one million, four hundred thirty-eight thousand, two hundred eight".