20011201221021 has 4 divisors (see below), whose sum is σ = 26681601628032. Its totient is φ = 13340800814012.

The previous prime is 20011201221017. The next prime is 20011201221049. The reversal of 20011201221021 is 12012210211002.

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 20011201221021 - 2² = 20011201221017 is a prime.

It is a super-2 number, since 2×20011201221021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011201221071) 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, 3335200203501 + ... + 3335200203506.

It is an arithmetic number, because the mean of its divisors is an integer number (6670400407008).

Almost surely, 2^{20011201221021} is an apocalyptic number.

It is an amenable number.

20011201221021 is a deficient number, since it is larger than the sum of its proper divisors (6670400407011).

20011201221021 is an equidigital number, since it uses as much as digits as its factorization.

20011201221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6670400407010.

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

Adding to 20011201221021 its reverse (12012210211002), we get a palindrome (32023411432023).

The spelling of 20011201221021 in words is "twenty trillion, eleven billion, two hundred one million, two hundred twenty-one thousand, twenty-one".