28723573840 has 80 divisors (see below), whose sum is σ = 71965425168. Its totient is φ = 10598842368.

The previous prime is 28723573789. The next prime is 28723573873. The reversal of 28723573840 is 4837532782.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1031951376 + 27691622464 = 32124^2 + 166408^2 .

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

It is a congruent number.

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, 1794352 + ... + 1810288.

Almost surely, 2^28723573840 is an apocalyptic number.

28723573840 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 28723573840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35982712584).

28723573840 is an abundant number, since it is smaller than the sum of its proper divisors (43241851328).

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

28723573840 is a wasteful number, since it uses less digits than its factorization.

28723573840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17696 (or 17690 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 49.

The spelling of 28723573840 in words is "twenty-eight billion, seven hundred twenty-three million, five hundred seventy-three thousand, eight hundred forty".