21328333 has 4 divisors (see below), whose sum is σ = 22968988. Its totient is φ = 19687680.

The previous prime is 21328327. The next prime is 21328339. The reversal of 21328333 is 33382312.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21328327) and next prime (21328339).

It can be written as a sum of positive squares in 2 ways, for example, as 9474084 + 11854249 = 3078^2 + 3443^2 .

It is a cyclic number.

It is not a de Polignac number, because 21328333 - 2⁹ = 21327821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21328298 and 21328307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 820308 + ... + 820333.

It is an arithmetic number, because the mean of its divisors is an integer number (5742247).

Almost surely, 2^21328333 is an apocalyptic number.

It is an amenable number.

21328333 is a deficient number, since it is larger than the sum of its proper divisors (1640655).

21328333 is a wasteful number, since it uses less digits than its factorization.

21328333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1640654.

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

The square root of 21328333 is about 4618.2608198325. The cubic root of 21328333 is about 277.3228390627.

The spelling of 21328333 in words is "twenty-one million, three hundred twenty-eight thousand, three hundred thirty-three".