28381705506 has 384 divisors, whose sum is σ = 84536524800. Its totient is φ = 6913719360.

The previous prime is 28381705489. The next prime is 28381705523. The reversal of 28381705506 is 60550718382.

28381705506 is a `hidden beast` number, since 2 + 83 + 8 + 17 + 0 + 550 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (28381705489) and next prime (28381705523).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 127272111 + ... + 127272333.

It is an arithmetic number, because the mean of its divisors is an integer number (220147200).

Almost surely, 2^28381705506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28381705506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42268262400).

28381705506 is an abundant number, since it is smaller than the sum of its proper divisors (56154819294).

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

28381705506 is a wasteful number, since it uses less digits than its factorization.

28381705506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456 (or 444 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 28381705506 in words is "twenty-eight billion, three hundred eighty-one million, seven hundred five thousand, five hundred six".