20121212122020 has 144 divisors (see below), whose sum is σ = 64662787229040. Its totient is φ = 5047045521408.

The previous prime is 20121212121979. The next prime is 20121212122027. The reversal of 20121212122020 is 2022121212102.

It is a happy number.

20121212122020 is a `hidden beast` number, since 201 + 212 + 1 + 212 + 20 + 20 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 550934784 + 20120661187236 = 23472^2 + 4485606^2 .

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 = 20121212121984 and 20121212122002.

It is not an unprimeable number, because it can be changed into a prime (20121212122027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3238596 + ... + 7122564.

It is an arithmetic number, because the mean of its divisors is an integer number (449047133535).

Almost surely, 2^{20121212122020} is an apocalyptic number.

20121212122020 is a gapful number since it is divisible by the number (20) 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 20121212122020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32331393614520).

20121212122020 is an abundant number, since it is smaller than the sum of its proper divisors (44541575107020).

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

20121212122020 is a wasteful number, since it uses less digits than its factorization.

20121212122020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3885694 (or 3885689 counting only the distinct ones).

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

Adding to 20121212122020 its reverse (2022121212102), we get a palindrome (22143333334122).

The spelling of 20121212122020 in words is "twenty trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty-two thousand, twenty".