20121221122020 has 72 divisors (see below), whose sum is σ = 61035255186360. Its totient is φ = 5365581212160.

The previous prime is 20121221121893. The next prime is 20121221122111. The reversal of 20121221122020 is 2022112212102.

It is a happy number.

20121221122020 is a `hidden beast` number, since 2 + 0 + 1 + 212 + 211 + 220 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 580241733696 + 19540979388324 = 761736^2 + 4420518^2 .

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 = 20121221121984 and 20121221122002.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 12227400 + ... + 13775040.

Almost surely, 2^{20121221122020} is an apocalyptic number.

20121221122020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121221122020 is an abundant number, since it is smaller than the sum of its proper divisors (40914034064340).

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

20121221122020 is a wasteful number, since it uses less digits than its factorization.

20121221122020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1619885 (or 1619880 counting only the distinct ones).

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

Adding to 20121221122020 its reverse (2022112212102), we get a palindrome (22143333334122).

The spelling of 20121221122020 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, twenty".