20211021221201 has 4 divisors (see below), whose sum is σ = 20542349438004. Its totient is φ = 19879693004400.

The previous prime is 20211021221177. The next prime is 20211021221329. The reversal of 20211021221201 is 10212212011202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 637121643601 + 19573899577600 = 798199^2 + 4424240^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211021221201 - 2⁶ = 20211021221137 is a prime.

It is a super-2 number, since 2×20211021221201² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20211021221201.

It is not an unprimeable number, because it can be changed into a prime (20211021224201) 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, 165664108310 + ... + 165664108431.

It is an arithmetic number, because the mean of its divisors is an integer number (5135587359501).

Almost surely, 2^{20211021221201} is an apocalyptic number.

It is an amenable number.

20211021221201 is a deficient number, since it is larger than the sum of its proper divisors (331328216803).

20211021221201 is an equidigital number, since it uses as much as digits as its factorization.

20211021221201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331328216802.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20211021221201 its reverse (10212212011202), we get a palindrome (30423233232403).

The spelling of 20211021221201 in words is "twenty trillion, two hundred eleven billion, twenty-one million, two hundred twenty-one thousand, two hundred one".