2001100021020 has 144 divisors (see below), whose sum is σ = 6375865047552. Its totient is φ = 507045052800.

The previous prime is 2001100020989. The next prime is 2001100021021. The reversal of 2001100021020 is 201200011002.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 2001100020993 and 2001100021011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001100021021) 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, 975382 + ... + 2225661.

It is an arithmetic number, because the mean of its divisors is an integer number (44276840608).

Almost surely, 2^{2001100021020} is an apocalyptic number.

2001100021020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001100021020 is an abundant number, since it is smaller than the sum of its proper divisors (4374765026532).

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

2001100021020 is a wasteful number, since it uses less digits than its factorization.

2001100021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3201232 (or 3201227 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 2001100021020 its reverse (201200011002), we get a palindrome (2202300032022).

The spelling of 2001100021020 in words is "two trillion, one billion, one hundred million, twenty-one thousand, twenty".