2001201020191 has 4 divisors (see below), whose sum is σ = 2001532955400. Its totient is φ = 2000869084984.

The previous prime is 2001201020053. The next prime is 2001201020201. The reversal of 2001201020191 is 1910201021002.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001201020191 is a prime.

It is a super-3 number, since 3×2001201020191³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001201000191) 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, 165958561 + ... + 165970618.

It is an arithmetic number, because the mean of its divisors is an integer number (500383238850).

Almost surely, 2^{2001201020191} is an apocalyptic number.

2001201020191 is a deficient number, since it is larger than the sum of its proper divisors (331935209).

2001201020191 is an equidigital number, since it uses as much as digits as its factorization.

2001201020191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331935208.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 2001201020191 its reverse (1910201021002), we get a palindrome (3911402041193).

The spelling of 2001201020191 in words is "two trillion, one billion, two hundred one million, twenty thousand, one hundred ninety-one".