28913997840 has 640 divisors, whose sum is σ = 118192435200. Its totient is φ = 5676687360.

The previous prime is 28913997829. The next prime is 28913997841. The reversal of 28913997840 is 4879931982.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (28913997841) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 24482050 + ... + 24483230.

It is an arithmetic number, because the mean of its divisors is an integer number (184675680).

Almost surely, 2^28913997840 is an apocalyptic number.

28913997840 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 28913997840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59096217600).

28913997840 is an abundant number, since it is smaller than the sum of its proper divisors (89278437360).

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

28913997840 is a wasteful number, since it uses less digits than its factorization.

28913997840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1295 (or 1289 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 60.

The spelling of 28913997840 in words is "twenty-eight billion, nine hundred thirteen million, nine hundred ninety-seven thousand, eight hundred forty".