28121933736 has 96 divisors (see below), whose sum is σ = 82314970920. Its totient is φ = 8622028800.

The previous prime is 28121933717. The next prime is 28121933759. The reversal of 28121933736 is 63733912182.

28121933736 is a `hidden beast` number, since 281 + 2 + 1 + 9 + 337 + 36 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 26832405636 + 1289528100 = 163806^2 + 35910^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28121933691 and 28121933700.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 209556 + ... + 316476.

Almost surely, 2^28121933736 is an apocalyptic number.

28121933736 is a gapful number since it is divisible by the number (26) 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 28121933736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41157485460).

28121933736 is an abundant number, since it is smaller than the sum of its proper divisors (54193037184).

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

28121933736 is a wasteful number, since it uses less digits than its factorization.

28121933736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107227 (or 107220 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The spelling of 28121933736 in words is "twenty-eight billion, one hundred twenty-one million, nine hundred thirty-three thousand, seven hundred thirty-six".