2001221111001 has 16 divisors (see below), whose sum is σ = 3092430210048. Its totient is φ = 1127448512400.

The previous prime is 2001221110981. The next prime is 2001221111003. The reversal of 2001221111001 is 1001111221002.

It is not a de Polignac number, because 2001221111001 - 2⁵ = 2001221110969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2001221111003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 671098815 + ... + 671101796.

It is an arithmetic number, because the mean of its divisors is an integer number (193276888128).

Almost surely, 2^{2001221111001} is an apocalyptic number.

2001221111001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2001221111001 is a deficient number, since it is larger than the sum of its proper divisors (1091209099047).

2001221111001 is a wasteful number, since it uses less digits than its factorization.

2001221111001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342200692.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 2001221111001 its reverse (1001111221002), we get a palindrome (3002332332003).

The spelling of 2001221111001 in words is "two trillion, one billion, two hundred twenty-one million, one hundred eleven thousand, one".