212121222144 has 176 divisors, whose sum is σ = 610665756288. Its totient is φ = 65075724288.

The previous prime is 212121222143. The next prime is 212121222161. The reversal of 212121222144 is 441222121212.

212121222144 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121222143) 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, 13850139 + ... + 13865445.

Almost surely, 2^212121222144 is an apocalyptic number.

212121222144 is a gapful number since it is divisible by the number (24) 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 212121222144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305332878144).

212121222144 is an abundant number, since it is smaller than the sum of its proper divisors (398544534144).

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

212121222144 is a wasteful number, since it uses less digits than its factorization.

212121222144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15690 (or 15672 counting only the distinct ones).

The product of its digits is 1024, while the sum is 24.

Adding to 212121222144 its reverse (441222121212), we get a palindrome (653343343356).

The spelling of 212121222144 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred forty-four".