28808720640 has 864 divisors, whose sum is σ = 119994900480. Its totient is φ = 6242697216.

The previous prime is 28808720623. The next prime is 28808720653. The reversal of 28808720640 is 4602780882.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 226840257 + ... + 226840383.

Almost surely, 2^28808720640 is an apocalyptic number.

28808720640 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 28808720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59997450240).

28808720640 is an abundant number, since it is smaller than the sum of its proper divisors (91186179840).

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

28808720640 is a wasteful number, since it uses less digits than its factorization.

28808720640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 45.

The spelling of 28808720640 in words is "twenty-eight billion, eight hundred eight million, seven hundred twenty thousand, six hundred forty".