28238729 has 2 divisors, whose sum is σ = 28238730. Its totient is φ = 28238728.

The previous prime is 28238723. The next prime is 28238741. The reversal of 28238729 is 92783282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27541504 + 697225 = 5248^2 + 835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28238729 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28238723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14119364 + 14119365.

It is an arithmetic number, because the mean of its divisors is an integer number (14119365).

Almost surely, 2^28238729 is an apocalyptic number.

It is an amenable number.

28238729 is a deficient number, since it is larger than the sum of its proper divisors (1).

28238729 is an equidigital number, since it uses as much as digits as its factorization.

28238729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 41.

The square root of 28238729 is about 5314.0125140989. The cubic root of 28238729 is about 304.5194582777.

The spelling of 28238729 in words is "twenty-eight million, two hundred thirty-eight thousand, seven hundred twenty-nine".