20001221222120 has 32 divisors (see below), whose sum is σ = 45057429169920. Its totient is φ = 7990767347520.

The previous prime is 20001221222111. The next prime is 20001221222131. The reversal of 20001221222120 is 2122212210002.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303752336 + ... + 303818175.

It is an arithmetic number, because the mean of its divisors is an integer number (1408044661560).

Almost surely, 2^{20001221222120} is an apocalyptic number.

20001221222120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20001221222120 is an abundant number, since it is smaller than the sum of its proper divisors (25056207947800).

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

20001221222120 is a wasteful number, since it uses less digits than its factorization.

20001221222120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607571345 (or 607571341 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 20001221222120 its reverse (2122212210002), we get a palindrome (22123433432122).

The spelling of 20001221222120 in words is "twenty trillion, one billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty".