28821779 has 16 divisors (see below), whose sum is σ = 34039488. Its totient is φ = 23887872.

The previous prime is 28821773. The next prime is 28821781. The reversal of 28821779 is 97712882.

It is a cyclic number.

It is not a de Polignac number, because 28821779 - 2¹⁶ = 28756243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28821773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66347 + ... + 66779.

It is an arithmetic number, because the mean of its divisors is an integer number (2127468).

Almost surely, 2^28821779 is an apocalyptic number.

28821779 is a deficient number, since it is larger than the sum of its proper divisors (5217709).

28821779 is a wasteful number, since it uses less digits than its factorization.

28821779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 734.

The product of its digits is 112896, while the sum is 44.

The square root of 28821779 is about 5368.5919010482. The cubic root of 28821779 is about 306.6010194757.

The spelling of 28821779 in words is "twenty-eight million, eight hundred twenty-one thousand, seven hundred seventy-nine".