212121212424 has 128 divisors (see below), whose sum is σ = 587313192960. Its totient is φ = 63308000000.

The previous prime is 212121212411. The next prime is 212121212449. The reversal of 212121212424 is 424212121212.

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 a junction number, because it is equal to n+sod(n) for n = 212121212394 and 212121212403.

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, 5071999 + ... + 5113649.

It is an arithmetic number, because the mean of its divisors is an integer number (4588384320).

Almost surely, 2^212121212424 is an apocalyptic number.

212121212424 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 212121212424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293656596480).

212121212424 is an abundant number, since it is smaller than the sum of its proper divisors (375191980536).

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

212121212424 is a wasteful number, since it uses less digits than its factorization.

212121212424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41963 (or 41959 counting only the distinct ones).

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

Adding to 212121212424 its reverse (424212121212), we get a palindrome (636333333636).

The spelling of 212121212424 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred twelve thousand, four hundred twenty-four".