221211211222201 has 16 divisors (see below), whose sum is σ = 224210973602448. Its totient is φ = 218227920768000.

The previous prime is 221211211222123. The next prime is 221211211222237. The reversal of 221211211222201 is 102222112112122.

It can be written as a sum of positive squares in 8 ways, for example, as 28865378767801 + 192345832454400 = 5372651^2 + 13868880^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211211222201 - 2¹⁹ = 221211210697913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221211211222801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72511485 + ... + 75500581.

It is an arithmetic number, because the mean of its divisors is an integer number (14013185850153).

Almost surely, 2^{221211211222201} is an apocalyptic number.

It is an amenable number.

221211211222201 is a deficient number, since it is larger than the sum of its proper divisors (2999762380247).

221211211222201 is a wasteful number, since it uses less digits than its factorization.

221211211222201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2991852.

The product of its (nonzero) digits is 256, while the sum is 22.

Adding to 221211211222201 its reverse (102222112112122), we get a palindrome (323433323334323).

The spelling of 221211211222201 in words is "two hundred twenty-one trillion, two hundred eleven billion, two hundred eleven million, two hundred twenty-two thousand, two hundred one".