28556881 has 2 divisors, whose sum is σ = 28556882. Its totient is φ = 28556880.

The previous prime is 28556873. The next prime is 28556903. The reversal of 28556881 is 18865582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28259856 + 297025 = 5316^2 + 545^2 .

It is a cyclic number.

It is not a de Polignac number, because 28556881 - 2³ = 28556873 is a prime.

It is a super-2 number, since 2×28556881² = 1630990904896322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28556831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14278440 + 14278441.

It is an arithmetic number, because the mean of its divisors is an integer number (14278441).

Almost surely, 2^28556881 is an apocalyptic number.

It is an amenable number.

28556881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28556881 is an equidigital number, since it uses as much as digits as its factorization.

28556881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 153600, while the sum is 43.

The square root of 28556881 is about 5343.8638642840. The cubic root of 28556881 is about 305.6588141933.

The spelling of 28556881 in words is "twenty-eight million, five hundred fifty-six thousand, eight hundred eighty-one".