28121113 has 2 divisors, whose sum is σ = 28121114. Its totient is φ = 28121112.

The previous prime is 28121101. The next prime is 28121117. The reversal of 28121113 is 31112182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14379264 + 13741849 = 3792^2 + 3707^2 .

It is a cyclic number.

It is not a de Polignac number, because 28121113 - 2⁵ = 28121081 is a prime.

It is not a weakly prime, because it can be changed into another prime (28121117) 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, 14060556 + 14060557.

It is an arithmetic number, because the mean of its divisors is an integer number (14060557).

Almost surely, 2^28121113 is an apocalyptic number.

It is an amenable number.

28121113 is a deficient number, since it is larger than the sum of its proper divisors (1).

28121113 is an equidigital number, since it uses as much as digits as its factorization.

28121113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 19.

The square root of 28121113 is about 5302.9343763618. The cubic root of 28121113 is about 304.0960893441.

Adding to 28121113 its reverse (31112182), we get a palindrome (59233295).

The spelling of 28121113 in words is "twenty-eight million, one hundred twenty-one thousand, one hundred thirteen".