20211020111005 has 4 divisors (see below), whose sum is σ = 24253224133212. Its totient is φ = 16168816088800.

The previous prime is 20211020110979. The next prime is 20211020111011. The reversal of 20211020111005 is 50011102011202.

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 6971770248921 + 13239249862084 = 2640411^2 + 3638578^2 .

It is not a de Polignac number, because 20211020111005 - 2⁷ = 20211020110877 is a prime.

It is a super-2 number, since 2×20211020111005² (a number of 27 digits) contains 22 as substring.

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 20211020111005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2021102011096 + ... + 2021102011105.

It is an arithmetic number, because the mean of its divisors is an integer number (6063306033303).

Almost surely, 2^{20211020111005} is an apocalyptic number.

It is an amenable number.

20211020111005 is a deficient number, since it is larger than the sum of its proper divisors (4042204022207).

20211020111005 is an equidigital number, since it uses as much as digits as its factorization.

20211020111005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4042204022206.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 20211020111005 its reverse (50011102011202), we get a palindrome (70222122122207).

The spelling of 20211020111005 in words is "twenty trillion, two hundred eleven billion, twenty million, one hundred eleven thousand, five".