28107881 has 2 divisors, whose sum is σ = 28107882. Its totient is φ = 28107880.

The previous prime is 28107857. The next prime is 28107887. The reversal of 28107881 is 18870182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22886656 + 5221225 = 4784^2 + 2285^2 .

It is a cyclic number.

It is not a de Polignac number, because 28107881 - 2¹⁸ = 27845737 is a prime.

It is a super-2 number, since 2×28107881² = 1580105948620322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28107887) 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, 14053940 + 14053941.

It is an arithmetic number, because the mean of its divisors is an integer number (14053941).

Almost surely, 2^28107881 is an apocalyptic number.

It is an amenable number.

28107881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28107881 is an equidigital number, since it uses as much as digits as its factorization.

28107881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 28107881 is about 5301.6866184263. The cubic root of 28107881 is about 304.0483857944.

The spelling of 28107881 in words is "twenty-eight million, one hundred seven thousand, eight hundred eighty-one".