28955221 has 8 divisors (see below), whose sum is σ = 30567200. Its totient is φ = 27352080.

The previous prime is 28955203. The next prime is 28955249. The reversal of 28955221 is 12255982.

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 28955221 - 2⁷ = 28955093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28955261) 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, 5191 + ... + 9211.

It is an arithmetic number, because the mean of its divisors is an integer number (3820900).

Almost surely, 2^28955221 is an apocalyptic number.

It is an amenable number.

28955221 is a deficient number, since it is larger than the sum of its proper divisors (1611979).

28955221 is a wasteful number, since it uses less digits than its factorization.

28955221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4419.

The product of its digits is 14400, while the sum is 34.

The square root of 28955221 is about 5381.0055751690. The cubic root of 28955221 is about 307.0734686076.

The spelling of 28955221 in words is "twenty-eight million, nine hundred fifty-five thousand, two hundred twenty-one".