20111221201021 has 4 divisors (see below), whose sum is σ = 20244408096544. Its totient is φ = 19978034305500.

The previous prime is 20111221200997. The next prime is 20111221201033. The reversal of 20111221201021 is 12010212211102.

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 20111221201021 - 2⁷ = 20111221200893 is a prime.

It is a super-2 number, since 2×20111221201021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111221200986 and 20111221201004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111221201061) 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, 66593447535 + ... + 66593447836.

It is an arithmetic number, because the mean of its divisors is an integer number (5061102024136).

Almost surely, 2^{20111221201021} is an apocalyptic number.

It is an amenable number.

20111221201021 is a deficient number, since it is larger than the sum of its proper divisors (133186895523).

20111221201021 is a wasteful number, since it uses less digits than its factorization.

20111221201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133186895522.

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

Adding to 20111221201021 its reverse (12010212211102), we get a palindrome (32121433412123).

The spelling of 20111221201021 in words is "twenty trillion, one hundred eleven billion, two hundred twenty-one million, two hundred one thousand, twenty-one".