21213311331212 has 144 divisors (see below), whose sum is σ = 50558541902400. Its totient is φ = 7577958136320.

The previous prime is 21213311331181. The next prime is 21213311331217.

21213311331212 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (21213311331217) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4946318 + ... + 8178794.

Almost surely, 2^{21213311331212} is an apocalyptic number.

21213311331212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21213311331212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25279270951200).

21213311331212 is an abundant number, since it is smaller than the sum of its proper divisors (29345230571188).

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

21213311331212 is a wasteful number, since it uses less digits than its factorization.

21213311331212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3232672 (or 3232659 counting only the distinct ones).

The product of its digits is 1296, while the sum is 26.

It can be divided in two parts, 2121331 and 1331212, that added together give a palindrome (3452543).

The spelling of 21213311331212 in words is "twenty-one trillion, two hundred thirteen billion, three hundred eleven million, three hundred thirty-one thousand, two hundred twelve".