2001221212001 has 12 divisors (see below), whose sum is σ = 2201197294800. Its totient is φ = 1818044906040.

The previous prime is 2001221211989. The next prime is 2001221212021. The reversal of 2001221212001 is 1002121221002.

It is a de Polignac number, because none of the positive numbers 2^k-2001221212001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001221212021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5491391 + ... + 5844468.

It is an arithmetic number, because the mean of its divisors is an integer number (183433107900).

Almost surely, 2^{2001221212001} is an apocalyptic number.

It is an amenable number.

2001221212001 is a deficient number, since it is larger than the sum of its proper divisors (199976082799).

2001221212001 is a wasteful number, since it uses less digits than its factorization.

2001221212001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11337340 (or 11337329 counting only the distinct ones).

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

Adding to 2001221212001 its reverse (1002121221002), we get a palindrome (3003342433003).

Subtracting from 2001221212001 its reverse (1002121221002), we obtain a palindrome (999099990999).

The spelling of 2001221212001 in words is "two trillion, one billion, two hundred twenty-one million, two hundred twelve thousand, one".