28131199 has 2 divisors, whose sum is σ = 28131200. Its totient is φ = 28131198.

The previous prime is 28131179. The next prime is 28131221. The reversal of 28131199 is 99113182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28131199 - 2¹¹ = 28129151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28131109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14065599 + 14065600.

It is an arithmetic number, because the mean of its divisors is an integer number (14065600).

Almost surely, 2^28131199 is an apocalyptic number.

28131199 is a deficient number, since it is larger than the sum of its proper divisors (1).

28131199 is an equidigital number, since it uses as much as digits as its factorization.

28131199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 34.

The square root of 28131199 is about 5303.8852740232. The cubic root of 28131199 is about 304.1324409937.

The spelling of 28131199 in words is "twenty-eight million, one hundred thirty-one thousand, one hundred ninety-nine".