28406565720 has 192 divisors, whose sum is σ = 99504568800. Its totient is φ = 6986649600.

The previous prime is 28406565709. The next prime is 28406565727. The reversal of 28406565720 is 2756560482.

28406565720 is a `hidden beast` number, since 2 + 84 + 0 + 6 + 565 + 7 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28406565727) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9962295 + ... + 9965145.

Almost surely, 2^28406565720 is an apocalyptic number.

28406565720 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 28406565720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49752284400).

28406565720 is an abundant number, since it is smaller than the sum of its proper divisors (71098003080).

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

28406565720 is a wasteful number, since it uses less digits than its factorization.

28406565720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5010 (or 5003 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The spelling of 28406565720 in words is "twenty-eight billion, four hundred six million, five hundred sixty-five thousand, seven hundred twenty".