28211321 has 8 divisors (see below), whose sum is σ = 29030400. Its totient is φ = 27398560.

The previous prime is 28211303. The next prime is 28211377. The reversal of 28211321 is 12311282.

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 28211321 - 2¹⁰ = 28210297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28211293 and 28211302.

It is not an unprimeable number, because it can be changed into a prime (28211021) 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, 8360 + ... + 11238.

It is an arithmetic number, because the mean of its divisors is an integer number (3628800).

Almost surely, 2^28211321 is an apocalyptic number.

It is an amenable number.

28211321 is a deficient number, since it is larger than the sum of its proper divisors (819079).

28211321 is a wasteful number, since it uses less digits than its factorization.

28211321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3159.

The product of its digits is 192, while the sum is 20.

The square root of 28211321 is about 5311.4330457985. The cubic root of 28211321 is about 304.4209060256.

The spelling of 28211321 in words is "twenty-eight million, two hundred eleven thousand, three hundred twenty-one".