21212122213 has 8 divisors (see below), whose sum is σ = 21934927008. Its totient is φ = 20501264784.

The previous prime is 21212122201. The next prime is 21212122219. The reversal of 21212122213 is 31222121212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212122213 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 (21212122219) 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 7 ways as a sum of consecutive naturals, for example, 2983231 + ... + 2990332.

It is an arithmetic number, because the mean of its divisors is an integer number (2741865876).

Almost surely, 2^21212122213 is an apocalyptic number.

It is an amenable number.

21212122213 is a deficient number, since it is larger than the sum of its proper divisors (722804795).

21212122213 is an equidigital number, since it uses as much as digits as its factorization.

21212122213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5973683.

The product of its digits is 192, while the sum is 19.

Adding to 21212122213 its reverse (31222121212), we get a palindrome (52434243425).

The spelling of 21212122213 in words is "twenty-one billion, two hundred twelve million, one hundred twenty-two thousand, two hundred thirteen".