2001001221220 has 24 divisors (see below), whose sum is σ = 4202791577208. Its totient is φ = 800269248000.

The previous prime is 2001001221211. The next prime is 2001001221287. The reversal of 2001001221220 is 221221001002.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 505683120996 + 1495318100224 = 711114^2 + 1222832^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2001001221220.

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, 8077461 + ... + 8321500.

It is an arithmetic number, because the mean of its divisors is an integer number (175116315717).

Almost surely, 2^{2001001221220} is an apocalyptic number.

2001001221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001001221220 is an abundant number, since it is smaller than the sum of its proper divisors (2201790355988).

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

2001001221220 is a wasteful number, since it uses less digits than its factorization.

2001001221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16405071 (or 16405069 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 2001001221220 its reverse (221221001002), we get a palindrome (2222222222222).

The spelling of 2001001221220 in words is "two trillion, one billion, one million, two hundred twenty-one thousand, two hundred twenty".