212121212120 has 64 divisors (see below), whose sum is σ = 513632080800. Its totient is φ = 78548244480.

The previous prime is 212121212101. The next prime is 212121212123. The reversal of 212121212120 is 21212121212.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121212123) 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, 2515430 + ... + 2598389.

Almost surely, 2^212121212120 is an apocalyptic number.

212121212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212121212120 is an abundant number, since it is smaller than the sum of its proper divisors (301510868680).

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

212121212120 is a wasteful number, since it uses less digits than its factorization.

212121212120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5113908 (or 5113904 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 212121212120 its reverse (21212121212), we get a palindrome (233333333332).

The spelling of 212121212120 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred twelve thousand, one hundred twenty".