21213111123213 has 16 divisors (see below), whose sum is σ = 28684547127936. Its totient is φ = 13941902804480.

The previous prime is 21213111123167. The next prime is 21213111123277. The reversal of 21213111123213 is 31232111131212.

It is a cyclic number.

It is not a de Polignac number, because 21213111123213 - 2¹² = 21213111119117 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213111123613) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 503820 + ... + 6532997.

It is an arithmetic number, because the mean of its divisors is an integer number (1792784195496).

Almost surely, 2^{21213111123213} is an apocalyptic number.

It is an amenable number.

21213111123213 is a deficient number, since it is larger than the sum of its proper divisors (7471436004723).

21213111123213 is a wasteful number, since it uses less digits than its factorization.

21213111123213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7051044.

The product of its digits is 432, while the sum is 24.

Adding to 21213111123213 its reverse (31232111131212), we get a palindrome (52445222254425).

The spelling of 21213111123213 in words is "twenty-one trillion, two hundred thirteen billion, one hundred eleven million, one hundred twenty-three thousand, two hundred thirteen".