28185791 has 2 divisors, whose sum is σ = 28185792. Its totient is φ = 28185790.

The previous prime is 28185757. The next prime is 28185799. The reversal of 28185791 is 19758182.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28185791 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28185799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14092895 + 14092896.

It is an arithmetic number, because the mean of its divisors is an integer number (14092896).

Almost surely, 2^28185791 is an apocalyptic number.

28185791 is a deficient number, since it is larger than the sum of its proper divisors (1).

28185791 is an equidigital number, since it uses as much as digits as its factorization.

28185791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 41.

The square root of 28185791 is about 5309.0291956251. The cubic root of 28185791 is about 304.3290491512.

The spelling of 28185791 in words is "twenty-eight million, one hundred eighty-five thousand, seven hundred ninety-one".