28213333 has 4 divisors (see below), whose sum is σ = 28225600. Its totient is φ = 28201068.

The previous prime is 28213327. The next prime is 28213337. The reversal of 28213333 is 33331282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a 3-Lehmer number, since φ(28213333) divides (28213333-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28213333 is a prime.

It is a Duffinian number.

28213333 is a modest number, since divided by 3333 gives 2821 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 28213298 and 28213307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28213337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1533 + ... + 7666.

It is an arithmetic number, because the mean of its divisors is an integer number (7056400).

Almost surely, 2^28213333 is an apocalyptic number.

28213333 is the 3067-th octagonal number.

It is an amenable number.

28213333 is a deficient number, since it is larger than the sum of its proper divisors (12267).

28213333 is an equidigital number, since it uses as much as digits as its factorization.

28213333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12266.

The product of its digits is 2592, while the sum is 25.

The square root of 28213333 is about 5311.6224451668. The cubic root of 28213333 is about 304.4281428403.

The spelling of 28213333 in words is "twenty-eight million, two hundred thirteen thousand, three hundred thirty-three".