20133221 has 8 divisors (see below), whose sum is σ = 20953080. Its totient is φ = 19321792.

The previous prime is 20133199. The next prime is 20133247. The reversal of 20133221 is 12233102.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 10982596 + 9150625 = 3314^2 + 3025^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20133221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20133196 and 20133205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20133251) 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 7 ways as a sum of consecutive naturals, for example, 3011 + ... + 7023.

It is an arithmetic number, because the mean of its divisors is an integer number (2619135).

Almost surely, 2^20133221 is an apocalyptic number.

It is an amenable number.

20133221 is a deficient number, since it is larger than the sum of its proper divisors (819859).

20133221 is a wasteful number, since it uses less digits than its factorization.

20133221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4215.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 20133221 is about 4487.0057945138. The cubic root of 20133221 is about 272.0431241098.

Adding to 20133221 its reverse (12233102), we get a palindrome (32366323).

The spelling of 20133221 in words is "twenty million, one hundred thirty-three thousand, two hundred twenty-one".