28250881 has 2 divisors, whose sum is σ = 28250882. Its totient is φ = 28250880.

The previous prime is 28250879. The next prime is 28250899. The reversal of 28250881 is 18805282.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26832400 + 1418481 = 5180^2 + 1191^2 .

It is a cyclic number.

It is not a de Polignac number, because 28250881 - 2¹ = 28250879 is a prime.

It is a super-2 number, since 2×28250881² = 1596224554552322, which contains 22 as substring.

Together with 28250879, it forms a pair of twin primes.

It is equal to p_1756078 and since 28250881 and 1756078 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (28250861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14125440 + 14125441.

It is an arithmetic number, because the mean of its divisors is an integer number (14125441).

Almost surely, 2^28250881 is an apocalyptic number.

It is an amenable number.

28250881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28250881 is an equidigital number, since it uses as much as digits as its factorization.

28250881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10240, while the sum is 34.

The square root of 28250881 is about 5315.1557832297. The cubic root of 28250881 is about 304.5631333993.

The spelling of 28250881 in words is "twenty-eight million, two hundred fifty thousand, eight hundred eighty-one".