28717729 has 2 divisors, whose sum is σ = 28717730. Its totient is φ = 28717728.

The previous prime is 28717727. The next prime is 28717747. The reversal of 28717729 is 92771782.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27583504 + 1134225 = 5252^2 + 1065^2 .

It is a cyclic number.

It is not a de Polignac number, because 28717729 - 2¹ = 28717727 is a prime.

Together with 28717727, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28717727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14358864 + 14358865.

It is an arithmetic number, because the mean of its divisors is an integer number (14358865).

Almost surely, 2^28717729 is an apocalyptic number.

It is an amenable number.

28717729 is a deficient number, since it is larger than the sum of its proper divisors (1).

28717729 is an equidigital number, since it uses as much as digits as its factorization.

28717729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98784, while the sum is 43.

The square root of 28717729 is about 5358.8925161828. The cubic root of 28717729 is about 306.2316193883.

The spelling of 28717729 in words is "twenty-eight million, seven hundred seventeen thousand, seven hundred twenty-nine".