28381267566 has 16 divisors (see below), whose sum is σ = 63069483600. Its totient is φ = 9460422504.

The previous prime is 28381267531. The next prime is 28381267601. The reversal of 28381267566 is 66576218382.

28381267566 is a `hidden beast` number, since 2 + 8 + 3 + 8 + 12 + 67 + 566 = 666.

It is an interprime number because it is at equal distance from previous prime (28381267531) and next prime (28381267601).

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 525579029 = 28381267566 / (2 + 8 + 3 + 8 + 1 + 2 + 6 + 7 + 5 + 6 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 262789461 + ... + 262789568.

It is an arithmetic number, because the mean of its divisors is an integer number (3941842725).

Almost surely, 2^28381267566 is an apocalyptic number.

28381267566 is an abundant number, since it is smaller than the sum of its proper divisors (34688216034).

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

28381267566 is a wasteful number, since it uses less digits than its factorization.

28381267566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525579040 (or 525579034 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The spelling of 28381267566 in words is "twenty-eight billion, three hundred eighty-one million, two hundred sixty-seven thousand, five hundred sixty-six".