2001221201001 has 32 divisors (see below), whose sum is σ = 2933633064960. Its totient is φ = 1203408228800.

The previous prime is 2001221200999. The next prime is 2001221201017. The reversal of 2001221201001 is 1001021221002.

It is a cyclic number.

It is not a de Polignac number, because 2001221201001 - 2¹ = 2001221200999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2001221201041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2043766 + ... + 2859968.

It is an arithmetic number, because the mean of its divisors is an integer number (91676033280).

Almost surely, 2^{2001221201001} is an apocalyptic number.

It is an amenable number.

2001221201001 is a deficient number, since it is larger than the sum of its proper divisors (932411863959).

2001221201001 is a wasteful number, since it uses less digits than its factorization.

2001221201001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816797.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 2001221201001 its reverse (1001021221002), we get a palindrome (3002242422003).

The spelling of 2001221201001 in words is "two trillion, one billion, two hundred twenty-one million, two hundred one thousand, one".