21331133 has 2 divisors, whose sum is σ = 21331134. Its totient is φ = 21331132.

The previous prime is 21331127. The next prime is 21331147. The reversal of 21331133 is 33113312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14915044 + 6416089 = 3862^2 + 2533^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331133 - 2¹⁴ = 21314749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21331103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665566 + 10665567.

It is an arithmetic number, because the mean of its divisors is an integer number (10665567).

Almost surely, 2^21331133 is an apocalyptic number.

It is an amenable number.

21331133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331133 is an equidigital number, since it uses as much as digits as its factorization.

21331133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162, while the sum is 17.

The square root of 21331133 is about 4618.5639543044. The cubic root of 21331133 is about 277.3349742504.

Adding to 21331133 its reverse (33113312), we get a palindrome (54444445).

The spelling of 21331133 in words is "twenty-one million, three hundred thirty-one thousand, one hundred thirty-three".