28787569 has 2 divisors, whose sum is σ = 28787570. Its totient is φ = 28787568.

The previous prime is 28787567. The next prime is 28787587. The reversal of 28787569 is 96578782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18386944 + 10400625 = 4288^2 + 3225^2 .

It is a cyclic number.

It is not a de Polignac number, because 28787569 - 2¹ = 28787567 is a prime.

It is a super-2 number, since 2×28787569² = 1657448257859522, which contains 22 as substring.

Together with 28787567, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28787567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14393784 + 14393785.

It is an arithmetic number, because the mean of its divisors is an integer number (14393785).

Almost surely, 2^28787569 is an apocalyptic number.

It is an amenable number.

28787569 is a deficient number, since it is larger than the sum of its proper divisors (1).

28787569 is an equidigital number, since it uses as much as digits as its factorization.

28787569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1693440, while the sum is 52.

The square root of 28787569 is about 5365.4048309517. The cubic root of 28787569 is about 306.4796647933.

The spelling of 28787569 in words is "twenty-eight million, seven hundred eighty-seven thousand, five hundred sixty-nine".