21000022111021 has 4 divisors (see below), whose sum is σ = 21000164090752. Its totient is φ = 20999880131292.

The previous prime is 21000022111001. The next prime is 21000022111073. The reversal of 21000022111021 is 12011122000012.

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 a de Polignac number, because none of the positive numbers 2^k-21000022111021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000022110992 and 21000022111010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000022111001) 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, 70767771 + ... + 71063896.

It is an arithmetic number, because the mean of its divisors is an integer number (5250041022688).

Almost surely, 2^{21000022111021} is an apocalyptic number.

It is an amenable number.

21000022111021 is a deficient number, since it is larger than the sum of its proper divisors (141979731).

21000022111021 is a wasteful number, since it uses less digits than its factorization.

21000022111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141979730.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21000022111021 its reverse (12011122000012), we get a palindrome (33011144111033).

The spelling of 21000022111021 in words is "twenty-one trillion, twenty-two million, one hundred eleven thousand, twenty-one".