21413333 has 4 divisors (see below), whose sum is σ = 21474348. Its totient is φ = 21352320.

The previous prime is 21413303. The next prime is 21413369. The reversal of 21413333 is 33331412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5866084 + 15547249 = 2422^2 + 3943^2 .

It is a cyclic number.

It is not a de Polignac number, because 21413333 - 2¹⁰ = 21412309 is a prime.

It is a Duffinian number.

21413333 is a modest number, since divided by 3333 gives 2141 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21413303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29978 + ... + 30683.

It is an arithmetic number, because the mean of its divisors is an integer number (5368587).

Almost surely, 2^21413333 is an apocalyptic number.

It is an amenable number.

21413333 is a deficient number, since it is larger than the sum of its proper divisors (61015).

21413333 is an equidigital number, since it uses as much as digits as its factorization.

21413333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61014.

The product of its digits is 648, while the sum is 20.

The square root of 21413333 is about 4627.4542677373. The cubic root of 21413333 is about 277.6907564863.

Adding to 21413333 its reverse (33331412), we get a palindrome (54744745).

The spelling of 21413333 in words is "twenty-one million, four hundred thirteen thousand, three hundred thirty-three".