2001021212220 has 96 divisors (see below), whose sum is σ = 5740522824960. Its totient is φ = 520499427840.

The previous prime is 2001021212213. The next prime is 2001021212231. The reversal of 2001021212220 is 222121201002.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 2001021212220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14541459 + ... + 14678421.

It is an arithmetic number, because the mean of its divisors is an integer number (59797112760).

Almost surely, 2^{2001021212220} is an apocalyptic number.

2001021212220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2001021212220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2870261412480).

2001021212220 is an abundant number, since it is smaller than the sum of its proper divisors (3739501612740).

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

2001021212220 is a wasteful number, since it uses less digits than its factorization.

2001021212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142955 (or 142953 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 2001021212220 its reverse (222121201002), we get a palindrome (2223142413222).

The spelling of 2001021212220 in words is "two trillion, one billion, twenty-one million, two hundred twelve thousand, two hundred twenty".