28723811868 has 96 divisors (see below), whose sum is σ = 78431360000. Its totient is φ = 9065727360.

The previous prime is 28723811867. The next prime is 28723811891. The reversal of 28723811868 is 86811832782.

28723811868 is a `hidden beast` number, since 2 + 87 + 2 + 381 + 186 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28723811863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6254253 + ... + 6258843.

Almost surely, 2^28723811868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28723811868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39215680000).

28723811868 is an abundant number, since it is smaller than the sum of its proper divisors (49707548132).

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

28723811868 is a wasteful number, since it uses less digits than its factorization.

28723811868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7672 (or 7664 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 54.

The spelling of 28723811868 in words is "twenty-eight billion, seven hundred twenty-three million, eight hundred eleven thousand, eight hundred sixty-eight".