28273210640 has 80 divisors (see below), whose sum is σ = 67261320000. Its totient is φ = 11049094656.

The previous prime is 28273210639. The next prime is 28273210681. The reversal of 28273210640 is 4601237282.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 28273210640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 750986 + ... + 787734.

It is an arithmetic number, because the mean of its divisors is an integer number (840766500).

Almost surely, 2^28273210640 is an apocalyptic number.

28273210640 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 28273210640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33630660000).

28273210640 is an abundant number, since it is smaller than the sum of its proper divisors (38988109360).

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

28273210640 is a wasteful number, since it uses less digits than its factorization.

28273210640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36984 (or 36978 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

The spelling of 28273210640 in words is "twenty-eight billion, two hundred seventy-three million, two hundred ten thousand, six hundred forty".