201211211112221 has 4 divisors (see below), whose sum is σ = 201389431849500. Its totient is φ = 201032990374944.

The previous prime is 201211211112199. The next prime is 201211211112257. The reversal of 201211211112221 is 122211112112102.

It is a happy number.

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 71831642376025 + 129379568736196 = 8475355^2 + 11374514^2 .

It is a cyclic number.

It is not a de Polignac number, because 201211211112221 - 2¹⁸ = 201211210850077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201211211112193 and 201211211112202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201211241112221) 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, 89110366946 + ... + 89110369203.

It is an arithmetic number, because the mean of its divisors is an integer number (50347357962375).

Almost surely, 2^{201211211112221} is an apocalyptic number.

It is an amenable number.

201211211112221 is a deficient number, since it is larger than the sum of its proper divisors (178220737279).

201211211112221 is a wasteful number, since it uses less digits than its factorization.

201211211112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178220737278.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 201211211112221 its reverse (122211112112102), we get a palindrome (323422323224323).

The spelling of 201211211112221 in words is "two hundred one trillion, two hundred eleven billion, two hundred eleven million, one hundred twelve thousand, two hundred twenty-one".