28001731 has 2 divisors, whose sum is σ = 28001732. Its totient is φ = 28001730.

The previous prime is 28001713. The next prime is 28001747. The reversal of 28001731 is 13710082.

Together with previous prime (28001713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28001731 is a prime.

It is a super-2 number, since 2×28001731² = 1568193877992722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28008731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14000865 + 14000866.

It is an arithmetic number, because the mean of its divisors is an integer number (14000866).

Almost surely, 2^28001731 is an apocalyptic number.

28001731 is a deficient number, since it is larger than the sum of its proper divisors (1).

28001731 is an equidigital number, since it uses as much as digits as its factorization.

28001731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 28001731 is about 5291.6661837270. Note that the first 3 decimals coincide. The cubic root of 28001731 is about 303.6651546009.

The spelling of 28001731 in words is "twenty-eight million, one thousand, seven hundred thirty-one".