12212121220020 has 72 divisors (see below), whose sum is σ = 37045500686376. Its totient is φ = 3256384004352.

The previous prime is 12212121219989. The next prime is 12212121220021. The reversal of 12212121220020 is 2002212121221.

It is a happy number.

12212121220020 is a `hidden beast` number, since 1 + 221 + 212 + 12 + 200 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7724519607204 + 4487601612816 = 2779302^2 + 2118396^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 12212121219975 and 12212121220002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12212121220021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1359114 + ... + 5125566.

Almost surely, 2^{12212121220020} is an apocalyptic number.

12212121220020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12212121220020 is an abundant number, since it is smaller than the sum of its proper divisors (24833379466356).

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

12212121220020 is a wasteful number, since it uses less digits than its factorization.

12212121220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3784481 (or 3784476 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 12212121220020 its reverse (2002212121221), we get a palindrome (14214333341241).

The spelling of 12212121220020 in words is "twelve trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twenty thousand, twenty".