28239131 has 2 divisors, whose sum is σ = 28239132. Its totient is φ = 28239130.

The previous prime is 28239083. The next prime is 28239139. The reversal of 28239131 is 13193282.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28239131 - 2⁶ = 28239067 is a prime.

It is a super-2 number, since 2×28239131² = 1594897039270322, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 28239094 and 28239103.

It is not a weakly prime, because it can be changed into another prime (28239139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14119565 + 14119566.

It is an arithmetic number, because the mean of its divisors is an integer number (14119566).

Almost surely, 2^28239131 is an apocalyptic number.

28239131 is a deficient number, since it is larger than the sum of its proper divisors (1).

28239131 is an equidigital number, since it uses as much as digits as its factorization.

28239131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 29.

The square root of 28239131 is about 5314.0503384895. The cubic root of 28239131 is about 304.5209032937.

The spelling of 28239131 in words is "twenty-eight million, two hundred thirty-nine thousand, one hundred thirty-one".