28228626921 has 8 divisors (see below), whose sum is σ = 41059821024. Its totient is φ = 17108258720.

The previous prime is 28228626911. The next prime is 28228626949. The reversal of 28228626921 is 12962682282.

It is a happy number.

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 28228626921 - 2¹¹ = 28228624873 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28228626911) 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, 427706436 + ... + 427706501.

It is an arithmetic number, because the mean of its divisors is an integer number (5132477628).

Almost surely, 2^28228626921 is an apocalyptic number.

It is an amenable number.

28228626921 is a deficient number, since it is larger than the sum of its proper divisors (12831194103).

28228626921 is a wasteful number, since it uses less digits than its factorization.

28228626921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855412951.

The product of its digits is 663552, while the sum is 48.

The spelling of 28228626921 in words is "twenty-eight billion, two hundred twenty-eight million, six hundred twenty-six thousand, nine hundred twenty-one".