21441213 has 8 divisors (see below), whose sum is σ = 31764800. Its totient is φ = 14294124.

The previous prime is 21441197. The next prime is 21441223. The reversal of 21441213 is 31214412.

It is not a de Polignac number, because 21441213 - 2⁴ = 21441197 is a prime.

It is a super-2 number, since 2×21441213² = 919451229822738, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21441223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397033 + ... + 397086.

It is an arithmetic number, because the mean of its divisors is an integer number (3970600).

Almost surely, 2^21441213 is an apocalyptic number.

It is an amenable number.

21441213 is a deficient number, since it is larger than the sum of its proper divisors (10323587).

21441213 is an equidigital number, since it uses as much as digits as its factorization.

21441213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794128 (or 794122 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21441213 is about 4630.4657433135. The cubic root of 21441213 is about 277.8112213185.

Adding to 21441213 its reverse (31214412), we get a palindrome (52655625).

The spelling of 21441213 in words is "twenty-one million, four hundred forty-one thousand, two hundred thirteen".