28897251 has 16 divisors (see below), whose sum is σ = 39674880. Its totient is φ = 18697280.

The previous prime is 28897249. The next prime is 28897283. The reversal of 28897251 is 15279882.

It is a cyclic number.

It is not a de Polignac number, because 28897251 - 2¹ = 28897249 is a prime.

It is a super-2 number, since 2×28897251² = 1670102230714002, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (28897201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28906 + ... + 29888.

It is an arithmetic number, because the mean of its divisors is an integer number (2479680).

Almost surely, 2^28897251 is an apocalyptic number.

28897251 is a deficient number, since it is larger than the sum of its proper divisors (10777629).

28897251 is a wasteful number, since it uses less digits than its factorization.

28897251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266.

The product of its digits is 80640, while the sum is 42.

The square root of 28897251 is about 5375.6163367562. The cubic root of 28897251 is about 306.8684055117.

The spelling of 28897251 in words is "twenty-eight million, eight hundred ninety-seven thousand, two hundred fifty-one".