28821569 has 8 divisors (see below), whose sum is σ = 33057600. Its totient is φ = 24615216.

The previous prime is 28821539. The next prime is 28821571. The reversal of 28821569 is 96512882.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28821569 - 2⁸ = 28821313 is a prime.

It is a super-2 number, since 2×28821569² = 1661365679243522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28821539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5294 + ... + 9255.

It is an arithmetic number, because the mean of its divisors is an integer number (4132200).

Almost surely, 2^28821569 is an apocalyptic number.

It is an amenable number.

28821569 is a deficient number, since it is larger than the sum of its proper divisors (4236031).

28821569 is a wasteful number, since it uses less digits than its factorization.

28821569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14839.

The product of its digits is 69120, while the sum is 41.

The square root of 28821569 is about 5368.5723428114. The cubic root of 28821569 is about 306.6002748262.

The spelling of 28821569 in words is "twenty-eight million, eight hundred twenty-one thousand, five hundred sixty-nine".