28566666381 has 64 divisors (see below), whose sum is σ = 42898242816. Its totient is φ = 16763904000.

The previous prime is 28566666353. The next prime is 28566666409. The reversal of 28566666381 is 18366666582.

It is an interprime number because it is at equal distance from previous prime (28566666353) and next prime (28566666409).

It is a de Polignac number, because none of the positive numbers 2^k-28566666381 is a prime.

It is a super-2 number, since 2×28566666381² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28566666281) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 33332905 + ... + 33333761.

It is an arithmetic number, because the mean of its divisors is an integer number (670285044).

Almost surely, 2^28566666381 is an apocalyptic number.

It is an amenable number.

28566666381 is a deficient number, since it is larger than the sum of its proper divisors (14331576435).

28566666381 is a wasteful number, since it uses less digits than its factorization.

28566666381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1182.

The product of its digits is 14929920, while the sum is 57.

It can be divided in two parts, 285 and 66666381, that added together give a palindrome (66666666).

The spelling of 28566666381 in words is "twenty-eight billion, five hundred sixty-six million, six hundred sixty-six thousand, three hundred eighty-one".