20018191111001 has 4 divisors (see below), whose sum is σ = 20018200871604. Its totient is φ = 20018181350400.

The previous prime is 20018191110991. The next prime is 20018191111007. The reversal of 20018191111001 is 10011119181002.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8816451501001 + 11201739610000 = 2969251^2 + 3346900^2 .

It is a cyclic number.

It is not a de Polignac number, because 20018191111001 - 2¹⁴ = 20018191094617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20018191111007) 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, 483560 + ... + 6345881.

It is an arithmetic number, because the mean of its divisors is an integer number (5004550217901).

Almost surely, 2^{20018191111001} is an apocalyptic number.

It is an amenable number.

20018191111001 is a deficient number, since it is larger than the sum of its proper divisors (9760603).

20018191111001 is an equidigital number, since it uses as much as digits as its factorization.

20018191111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9760602.

The product of its (nonzero) digits is 144, while the sum is 26.

The spelling of 20018191111001 in words is "twenty trillion, eighteen billion, one hundred ninety-one million, one hundred eleven thousand, one".