28135231 has 2 divisors, whose sum is σ = 28135232. Its totient is φ = 28135230.

The previous prime is 28135193. The next prime is 28135277. The reversal of 28135231 is 13253182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28135231 - 2⁹ = 28134719 is a prime.

It is a super-2 number, since 2×28135231² = 1583182446846722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28135196 and 28135205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28135031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14067615 + 14067616.

It is an arithmetic number, because the mean of its divisors is an integer number (14067616).

Almost surely, 2^28135231 is an apocalyptic number.

28135231 is a deficient number, since it is larger than the sum of its proper divisors (1).

28135231 is an equidigital number, since it uses as much as digits as its factorization.

28135231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 28135231 is about 5304.2653591237. The cubic root of 28135231 is about 304.1469705726.

The spelling of 28135231 in words is "twenty-eight million, one hundred thirty-five thousand, two hundred thirty-one".