20213213 has 4 divisors (see below), whose sum is σ = 20223420. Its totient is φ = 20203008.

The previous prime is 20213197. The next prime is 20213233. The reversal of 20213213 is 31231202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9467929 + 10745284 = 3077^2 + 3278^2 .

It is a cyclic number.

It is not a de Polignac number, because 20213213 - 2⁴ = 20213197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20213233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1070 + ... + 6447.

It is an arithmetic number, because the mean of its divisors is an integer number (5055855).

Almost surely, 2^20213213 is an apocalyptic number.

It is an amenable number.

20213213 is a deficient number, since it is larger than the sum of its proper divisors (10207).

20213213 is an equidigital number, since it uses as much as digits as its factorization.

20213213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10206.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 20213213 is about 4495.9106975117. The cubic root of 20213213 is about 272.4029359993.

Adding to 20213213 its reverse (31231202), we get a palindrome (51444415).

The spelling of 20213213 in words is "twenty million, two hundred thirteen thousand, two hundred thirteen".