28731404844 has 18 divisors (see below), whose sum is σ = 72626606780. Its totient is φ = 9577134936.

The previous prime is 28731404843. The next prime is 28731404869. The reversal of 28731404844 is 44840413782.

28731404844 is a `hidden beast` number, since 28 + 7 + 3 + 140 + 484 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 28731404844.

It is not an unprimeable number, because it can be changed into a prime (28731404843) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 399047254 + ... + 399047325.

Almost surely, 2^28731404844 is an apocalyptic number.

It is an amenable number.

28731404844 is an abundant number, since it is smaller than the sum of its proper divisors (43895201936).

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

28731404844 is a wasteful number, since it uses less digits than its factorization.

28731404844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798094589 (or 798094584 counting only the distinct ones).

The product of its (nonzero) digits is 688128, while the sum is 45.

The spelling of 28731404844 in words is "twenty-eight billion, seven hundred thirty-one million, four hundred four thousand, eight hundred forty-four".