28289687720 has 64 divisors (see below), whose sum is σ = 72846604800. Its totient is φ = 9685762560.

The previous prime is 28289687707. The next prime is 28289687731. The reversal of 28289687720 is 2778698282.

It is a self number, because there is not a number n which added to its sum of digits gives 28289687720.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131060 + ... + 271580.

It is an arithmetic number, because the mean of its divisors is an integer number (1138228200).

Almost surely, 2^28289687720 is an apocalyptic number.

28289687720 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 28289687720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36423302400).

28289687720 is an abundant number, since it is smaller than the sum of its proper divisors (44556917080).

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

28289687720 is a wasteful number, since it uses less digits than its factorization.

28289687720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141258 (or 141254 counting only the distinct ones).

The product of its (nonzero) digits is 10838016, while the sum is 59.

The spelling of 28289687720 in words is "twenty-eight billion, two hundred eighty-nine million, six hundred eighty-seven thousand, seven hundred twenty".