2001221212120 has 64 divisors (see below), whose sum is σ = 4856972893920. Its totient is φ = 737714740224.

The previous prime is 2001221212117. The next prime is 2001221212157. The reversal of 2001221212120 is 212121221002.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 2001221212094 and 2001221212103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2797882 + ... + 3439561.

Almost surely, 2^{2001221212120} is an apocalyptic number.

2001221212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001221212120 is an abundant number, since it is smaller than the sum of its proper divisors (2855751681800).

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

2001221212120 is a wasteful number, since it uses less digits than its factorization.

2001221212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6238084 (or 6238080 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2001221212120 its reverse (212121221002), we get a palindrome (2213342433122).

The spelling of 2001221212120 in words is "two trillion, one billion, two hundred twenty-one million, two hundred twelve thousand, one hundred twenty".