2001221121020 has 48 divisors (see below), whose sum is σ = 4584782992608. Its totient is φ = 727690210560.

The previous prime is 2001221121013. The next prime is 2001221121047. The reversal of 2001221121020 is 201211221002.

It is a junction number, because it is equal to n+sod(n) for n = 2001221120986 and 2001221121004.

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, 6478322 + ... + 6780198.

It is an arithmetic number, because the mean of its divisors is an integer number (95516312346).

Almost surely, 2^{2001221121020} is an apocalyptic number.

2001221121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001221121020 is an abundant number, since it is smaller than the sum of its proper divisors (2583561871588).

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

2001221121020 is a wasteful number, since it uses less digits than its factorization.

2001221121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332030 (or 332028 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 2001221121020 its reverse (201211221002), we get a palindrome (2202432342022).

The spelling of 2001221121020 in words is "two trillion, one billion, two hundred twenty-one million, one hundred twenty-one thousand, twenty".