21112020011221 has 4 divisors (see below), whose sum is σ = 22223178959200. Its totient is φ = 20000861063244.

The previous prime is 21112020011219. The next prime is 21112020011273. The reversal of 21112020011221 is 12211002021112.

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 21112020011221 - 2¹ = 21112020011219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112020011195 and 21112020011204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112020011821) 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, 555579473961 + ... + 555579473998.

It is an arithmetic number, because the mean of its divisors is an integer number (5555794739800).

Almost surely, 2^{21112020011221} is an apocalyptic number.

It is an amenable number.

21112020011221 is a deficient number, since it is larger than the sum of its proper divisors (1111158947979).

21112020011221 is a wasteful number, since it uses less digits than its factorization.

21112020011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111158947978.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21112020011221 its reverse (12211002021112), we get a palindrome (33323022032333).

The spelling of 21112020011221 in words is "twenty-one trillion, one hundred twelve billion, twenty million, eleven thousand, two hundred twenty-one".