221220211211201 has 4 divisors (see below), whose sum is σ = 221220243218004. Its totient is φ = 221220179204400.

The previous prime is 221220211211161. The next prime is 221220211211291. The reversal of 221220211211201 is 102112112022122.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 53651742820225 + 167568468390976 = 7324735^2 + 12944824^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220211211201 - 2¹⁸ = 221220210949057 is a prime.

It is a super-2 number, since 2×221220211211201² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221220211211291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 858290 + ... + 21051771.

It is an arithmetic number, because the mean of its divisors is an integer number (55305060804501).

Almost surely, 2^{221220211211201} is an apocalyptic number.

It is an amenable number.

221220211211201 is a deficient number, since it is larger than the sum of its proper divisors (32006803).

221220211211201 is a wasteful number, since it uses less digits than its factorization.

221220211211201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32006802.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 221220211211201 its reverse (102112112022122), we get a palindrome (323332323233323).

The spelling of 221220211211201 in words is "two hundred twenty-one trillion, two hundred twenty billion, two hundred eleven million, two hundred eleven thousand, two hundred one".