28279861 has 2 divisors, whose sum is σ = 28279862. Its totient is φ = 28279860.

The previous prime is 28279859. The next prime is 28279871. The reversal of 28279861 is 16897282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21022225 + 7257636 = 4585^2 + 2694^2 .

It is a cyclic number.

It is not a de Polignac number, because 28279861 - 2¹ = 28279859 is a prime.

Together with 28279859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28279871) 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, 14139930 + 14139931.

It is an arithmetic number, because the mean of its divisors is an integer number (14139931).

Almost surely, 2^28279861 is an apocalyptic number.

It is an amenable number.

28279861 is a deficient number, since it is larger than the sum of its proper divisors (1).

28279861 is an equidigital number, since it uses as much as digits as its factorization.

28279861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 28279861 is about 5317.8812510247. The cubic root of 28279861 is about 304.6672389823.

The spelling of 28279861 in words is "twenty-eight million, two hundred seventy-nine thousand, eight hundred sixty-one".