21434213 has 2 divisors, whose sum is σ = 21434214. Its totient is φ = 21434212.

The previous prime is 21434177. The next prime is 21434221. The reversal of 21434213 is 31243412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21224449 + 209764 = 4607^2 + 458^2 .

It is a cyclic number.

It is not a de Polignac number, because 21434213 - 2¹² = 21430117 is a prime.

It is a super-3 number, since 3×21434213³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21434233) 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 as a sum of consecutive naturals, namely, 10717106 + 10717107.

It is an arithmetic number, because the mean of its divisors is an integer number (10717107).

Almost surely, 2^21434213 is an apocalyptic number.

It is an amenable number.

21434213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21434213 is an equidigital number, since it uses as much as digits as its factorization.

21434213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 20.

The square root of 21434213 is about 4629.7098181204. The cubic root of 21434213 is about 277.7809853081.

Adding to 21434213 its reverse (31243412), we get a palindrome (52677625).

The spelling of 21434213 in words is "twenty-one million, four hundred thirty-four thousand, two hundred thirteen".