2001231311201 has 4 divisors (see below), whose sum is σ = 2003874946452. Its totient is φ = 1998587675952.

The previous prime is 2001231311197. The next prime is 2001231311237. The reversal of 2001231311201 is 1021131321002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 990303619600 + 1010927691601 = 995140^2 + 1005449^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001231311201 - 2² = 2001231311197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2001231311201.

It is not an unprimeable number, because it can be changed into a prime (2001231311251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1321816490 + ... + 1321818003.

It is an arithmetic number, because the mean of its divisors is an integer number (500968736613).

Almost surely, 2^{2001231311201} is an apocalyptic number.

It is an amenable number.

2001231311201 is a deficient number, since it is larger than the sum of its proper divisors (2643635251).

2001231311201 is an equidigital number, since it uses as much as digits as its factorization.

2001231311201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2643635250.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 2001231311201 its reverse (1021131321002), we get a palindrome (3022362632203).

The spelling of 2001231311201 in words is "two trillion, one billion, two hundred thirty-one million, three hundred eleven thousand, two hundred one".