20111021220021 has 4 divisors (see below), whose sum is σ = 26814694960032. Its totient is φ = 13407347480012.

The previous prime is 20111021220013. The next prime is 20111021220041. The reversal of 20111021220021 is 12002212011102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20111021220021 - 2³ = 20111021220013 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111021220041) 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, 3351836870001 + ... + 3351836870006.

It is an arithmetic number, because the mean of its divisors is an integer number (6703673740008).

Almost surely, 2^{20111021220021} is an apocalyptic number.

It is an amenable number.

20111021220021 is a deficient number, since it is larger than the sum of its proper divisors (6703673740011).

20111021220021 is an equidigital number, since it uses as much as digits as its factorization.

20111021220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6703673740010.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20111021220021 its reverse (12002212011102), we get a palindrome (32113233231123).

The spelling of 20111021220021 in words is "twenty trillion, one hundred eleven billion, twenty-one million, two hundred twenty thousand, twenty-one".