21213113121312 has 192 divisors, whose sum is σ = 66461071380480. Its totient is φ = 5792588043264.

The previous prime is 21213113121287. The next prime is 21213113121331. The reversal of 21213113121312 is 21312131131212.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18182389 + ... + 19313867.

It is an arithmetic number, because the mean of its divisors is an integer number (346151413440).

Almost surely, 2^{21213113121312} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21213113121312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33230535690240).

21213113121312 is an abundant number, since it is smaller than the sum of its proper divisors (45247958259168).

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

21213113121312 is a wasteful number, since it uses less digits than its factorization.

21213113121312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132735 (or 1132727 counting only the distinct ones).

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

Adding to 21213113121312 its reverse (21312131131212), we get a palindrome (42525244252524).

The spelling of 21213113121312 in words is "twenty-one trillion, two hundred thirteen billion, one hundred thirteen million, one hundred twenty-one thousand, three hundred twelve".