20010111021191 has 4 divisors (see below), whose sum is σ = 20064634484832. Its totient is φ = 19955587557552.

The previous prime is 20010111021163. The next prime is 20010111021209. The reversal of 20010111021191 is 19112011101002.

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

It is a cyclic number.

It is not a de Polignac number, because 20010111021191 - 2³⁰ = 20009037279367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010111021151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27261731270 + ... + 27261732003.

It is an arithmetic number, because the mean of its divisors is an integer number (5016158621208).

Almost surely, 2^{20010111021191} is an apocalyptic number.

20010111021191 is a deficient number, since it is larger than the sum of its proper divisors (54523463641).

20010111021191 is an equidigital number, since it uses as much as digits as its factorization.

20010111021191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54523463640.

The product of its (nonzero) digits is 36, while the sum is 20.

Adding to 20010111021191 its reverse (19112011101002), we get a palindrome (39122122122193).

The spelling of 20010111021191 in words is "twenty trillion, ten billion, one hundred eleven million, twenty-one thousand, one hundred ninety-one".