221211211123 has 4 divisors (see below), whose sum is σ = 252812812720. Its totient is φ = 189609609528.

The previous prime is 221211211121. The next prime is 221211211129. The reversal of 221211211123 is 321112112122.

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

It is a cyclic number.

It is not a de Polignac number, because 221211211123 - 2¹ = 221211211121 is a prime.

It is a super-2 number, since 2×221211211123² (a number of 23 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 221211211123.

It is not an unprimeable number, because it can be changed into a prime (221211211121) 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, 15800800788 + ... + 15800800801.

It is an arithmetic number, because the mean of its divisors is an integer number (63203203180).

Almost surely, 2^221211211123 is an apocalyptic number.

221211211123 is a deficient number, since it is larger than the sum of its proper divisors (31601601597).

221211211123 is an equidigital number, since it uses as much as digits as its factorization.

221211211123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31601601596.

The product of its digits is 96, while the sum is 19.

Adding to 221211211123 its reverse (321112112122), we get a palindrome (542323323245).

Subtracting 221211211123 from its reverse (321112112122), we obtain a palindrome (99900900999).

The spelling of 221211211123 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred eleven thousand, one hundred twenty-three".