21219213 has 16 divisors (see below), whose sum is σ = 30991680. Its totient is φ = 12854016.

The previous prime is 21219203. The next prime is 21219259. The reversal of 21219213 is 31291212.

It is not a de Polignac number, because 21219213 - 2⁸ = 21218957 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21219213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21219203) 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, 5695 + ... + 8652.

It is an arithmetic number, because the mean of its divisors is an integer number (1936980).

Almost surely, 2^21219213 is an apocalyptic number.

It is an amenable number.

21219213 is a deficient number, since it is larger than the sum of its proper divisors (9772467).

21219213 is a wasteful number, since it uses less digits than its factorization.

21219213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14396.

The product of its digits is 216, while the sum is 21.

The square root of 21219213 is about 4606.4316992657. The cubic root of 21219213 is about 276.8490839051.

The spelling of 21219213 in words is "twenty-one million, two hundred nineteen thousand, two hundred thirteen".