2001221212403 has 16 divisors (see below), whose sum is σ = 2318677117440. Its totient is φ = 1691661900096.

The previous prime is 2001221212391. The next prime is 2001221212513. The reversal of 2001221212403 is 3042121221002.

It is not a de Polignac number, because 2001221212403 - 2¹⁴ = 2001221196019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001221112403) 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, 4934876 + ... + 5324982.

It is an arithmetic number, because the mean of its divisors is an integer number (144917319840).

Almost surely, 2^{2001221212403} is an apocalyptic number.

2001221212403 is a deficient number, since it is larger than the sum of its proper divisors (317455905037).

2001221212403 is a wasteful number, since it uses less digits than its factorization.

2001221212403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400226.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 2001221212403 its reverse (3042121221002), we get a palindrome (5043342433405).

The spelling of 2001221212403 in words is "two trillion, one billion, two hundred twenty-one million, two hundred twelve thousand, four hundred three".