28921579 has 4 divisors (see below), whose sum is σ = 29099176. Its totient is φ = 28743984.

The previous prime is 28921577. The next prime is 28921589. The reversal of 28921579 is 97512982.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28921579 - 2¹ = 28921577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28921577) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88554 + ... + 88879.

It is an arithmetic number, because the mean of its divisors is an integer number (7274794).

Almost surely, 2^28921579 is an apocalyptic number.

28921579 is a deficient number, since it is larger than the sum of its proper divisors (177597).

28921579 is a wasteful number, since it uses less digits than its factorization.

28921579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177596.

The product of its digits is 90720, while the sum is 43.

The square root of 28921579 is about 5377.8786710003. The cubic root of 28921579 is about 306.9544967519.

The spelling of 28921579 in words is "twenty-eight million, nine hundred twenty-one thousand, five hundred seventy-nine".