21212013213 has 16 divisors (see below), whose sum is σ = 31481645760. Its totient is φ = 14115943728.

The previous prime is 21212013197. The next prime is 21212013227. The reversal of 21212013213 is 31231021212.

It is not a de Polignac number, because 21212013213 - 2⁴ = 21212013197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212013113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 690195 + ... + 720272.

It is an arithmetic number, because the mean of its divisors is an integer number (1967602860).

Almost surely, 2^21212013213 is an apocalyptic number.

It is an amenable number.

21212013213 is a deficient number, since it is larger than the sum of its proper divisors (10269632547).

21212013213 is a wasteful number, since it uses less digits than its factorization.

21212013213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1411033 (or 1411027 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21212013213 its reverse (31231021212), we get a palindrome (52443034425).

The spelling of 21212013213 in words is "twenty-one billion, two hundred twelve million, thirteen thousand, two hundred thirteen".