20001121110021 has 4 divisors (see below), whose sum is σ = 26668161480032. Its totient is φ = 13334080740012.

The previous prime is 20001121110013. The next prime is 20001121110023. The reversal of 20001121110021 is 12001112110002.

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 not a de Polignac number, because 20001121110021 - 2³ = 20001121110013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20001121109979 and 20001121110006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001121110023) 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, 3333520185001 + ... + 3333520185006.

It is an arithmetic number, because the mean of its divisors is an integer number (6667040370008).

Almost surely, 2^{20001121110021} is an apocalyptic number.

It is an amenable number.

20001121110021 is a deficient number, since it is larger than the sum of its proper divisors (6667040370011).

20001121110021 is an equidigital number, since it uses as much as digits as its factorization.

20001121110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6667040370010.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20001121110021 its reverse (12001112110002), we get a palindrome (32002233220023).

The spelling of 20001121110021 in words is "twenty trillion, one billion, one hundred twenty-one million, one hundred ten thousand, twenty-one".