21433213 has 2 divisors, whose sum is σ = 21433214. Its totient is φ = 21433212.

The previous prime is 21433207. The next prime is 21433219. The reversal of 21433213 is 31233412.

It is a balanced prime because it is at equal distance from previous prime (21433207) and next prime (21433219).

It can be written as a sum of positive squares in only one way, i.e., 12830724 + 8602489 = 3582^2 + 2933^2 .

It is a cyclic number.

It is not a de Polignac number, because 21433213 - 2⁹ = 21432701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21433219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716606 + 10716607.

It is an arithmetic number, because the mean of its divisors is an integer number (10716607).

Almost surely, 2^21433213 is an apocalyptic number.

It is an amenable number.

21433213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21433213 is an equidigital number, since it uses as much as digits as its factorization.

21433213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 19.

The square root of 21433213 is about 4629.6018187313. The cubic root of 21433213 is about 277.7766653407.

Adding to 21433213 its reverse (31233412), we get a palindrome (52666625).

It can be divided in two parts, 2143 and 3213, that added together give a triangular number (5356 = T₁₀₃).

The spelling of 21433213 in words is "twenty-one million, four hundred thirty-three thousand, two hundred thirteen".