20211213 has 16 divisors (see below), whose sum is σ = 30194496. Its totient is φ = 11917440.

The previous prime is 20211209. The next prime is 20211221. The reversal of 20211213 is 31211202.

It is not a de Polignac number, because 20211213 - 2² = 20211209 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7056 + ... + 9497.

It is an arithmetic number, because the mean of its divisors is an integer number (1887156).

Almost surely, 2^20211213 is an apocalyptic number.

It is an amenable number.

20211213 is a deficient number, since it is larger than the sum of its proper divisors (9983283).

20211213 is a wasteful number, since it uses less digits than its factorization.

20211213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16604.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 20211213 is about 4495.6882676627. The cubic root of 20211213 is about 272.3939513838.

Adding to 20211213 its reverse (31211202), we get a palindrome (51422415).

The spelling of 20211213 in words is "twenty million, two hundred eleven thousand, two hundred thirteen".