28743881 has 2 divisors, whose sum is σ = 28743882. Its totient is φ = 28743880.

The previous prime is 28743877. The next prime is 28743887. The reversal of 28743881 is 18834782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16605625 + 12138256 = 4075^2 + 3484^2 .

It is a cyclic number.

It is not a de Polignac number, because 28743881 - 2² = 28743877 is a prime.

It is a super-3 number, since 3×28743881³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28743887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14371940 + 14371941.

It is an arithmetic number, because the mean of its divisors is an integer number (14371941).

Almost surely, 2^28743881 is an apocalyptic number.

It is an amenable number.

28743881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28743881 is an equidigital number, since it uses as much as digits as its factorization.

28743881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 86016, while the sum is 41.

The square root of 28743881 is about 5361.3320173255. The cubic root of 28743881 is about 306.3245485044.

Subtracting from 28743881 its reverse (18834782), we obtain a palindrome (9909099).

The spelling of 28743881 in words is "twenty-eight million, seven hundred forty-three thousand, eight hundred eighty-one".