21143213 has 16 divisors (see below), whose sum is σ = 26146176. Its totient is φ = 16649280.

The previous prime is 21143207. The next prime is 21143251. The reversal of 21143213 is 31234112.

It is a cyclic number.

It is not a de Polignac number, because 21143213 - 2⁴ = 21143197 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21143191 and 21143200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143203) 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 in 15 ways as a sum of consecutive naturals, for example, 25343 + ... + 26163.

It is an arithmetic number, because the mean of its divisors is an integer number (1634136).

Almost surely, 2^21143213 is an apocalyptic number.

It is an amenable number.

21143213 is a deficient number, since it is larger than the sum of its proper divisors (5002963).

21143213 is a wasteful number, since it uses less digits than its factorization.

21143213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124.

The product of its digits is 144, while the sum is 17.

The square root of 21143213 is about 4598.1749640482. The cubic root of 21143213 is about 276.5181621050.

Adding to 21143213 its reverse (31234112), we get a palindrome (52377325).

The spelling of 21143213 in words is "twenty-one million, one hundred forty-three thousand, two hundred thirteen".