28897709 has 2 divisors, whose sum is σ = 28897710. Its totient is φ = 28897708.

The previous prime is 28897699. The next prime is 28897721. The reversal of 28897709 is 90779882.

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., 27510025 + 1387684 = 5245^2 + 1178^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28897709 is a 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 (28897769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14448854 + 14448855.

It is an arithmetic number, because the mean of its divisors is an integer number (14448855).

Almost surely, 2^28897709 is an apocalyptic number.

It is an amenable number.

28897709 is a deficient number, since it is larger than the sum of its proper divisors (1).

28897709 is an equidigital number, since it uses as much as digits as its factorization.

28897709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 50.

The square root of 28897709 is about 5375.6589363538. The cubic root of 28897709 is about 306.8700267154.

The spelling of 28897709 in words is "twenty-eight million, eight hundred ninety-seven thousand, seven hundred nine".