21223213 has 8 divisors (see below), whose sum is σ = 23186016. Its totient is φ = 19266000.

The previous prime is 21223193. The next prime is 21223219. The reversal of 21223213 is 31232212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21223213 - 2¹³ = 21215021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223219) 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, 13570 + ... + 15052.

It is an arithmetic number, because the mean of its divisors is an integer number (2898252).

Almost surely, 2^21223213 is an apocalyptic number.

It is an amenable number.

21223213 is a deficient number, since it is larger than the sum of its proper divisors (1962803).

21223213 is a wasteful number, since it uses less digits than its factorization.

21223213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2795.

The product of its digits is 144, while the sum is 16.

The square root of 21223213 is about 4606.8658543526. The cubic root of 21223213 is about 276.8664789385.

Adding to 21223213 its reverse (31232212), we get a palindrome (52455425).

It can be divided in two parts, 2122 and 3213, that added together give a palindrome (5335).

The spelling of 21223213 in words is "twenty-one million, two hundred twenty-three thousand, two hundred thirteen".