21213111121212 has 48 divisors (see below), whose sum is σ = 49718695918752. Its totient is φ = 7039449123840.

The previous prime is 21213111121121. The next prime is 21213111121231. The reversal of 21213111121212 is 21212111131212.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 831738 + ... + 6566430.

It is an arithmetic number, because the mean of its divisors is an integer number (1035806164974).

Almost surely, 2^{21213111121212} is an apocalyptic number.

It is an amenable number.

21213111121212 is an abundant number, since it is smaller than the sum of its proper divisors (28505584797540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21213111121212 is a wasteful number, since it uses less digits than its factorization.

21213111121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5736078 (or 5736076 counting only the distinct ones).

The product of its digits is 96, while the sum is 21.

Adding to 21213111121212 its reverse (21212111131212), we get a palindrome (42425222252424).

The spelling of 21213111121212 in words is "twenty-one trillion, two hundred thirteen billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twelve".