221220121123 has 4 divisors (see below), whose sum is σ = 222268557928. Its totient is φ = 220171684320.

The previous prime is 221220121061. The next prime is 221220121127. The reversal of 221220121123 is 321121022122.

221220121123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221220121123 is a prime.

It is a super-2 number, since 2×221220121123² (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 221220121123.

It is not an unprimeable number, because it can be changed into a prime (221220121127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 524218086 + ... + 524218507.

It is an arithmetic number, because the mean of its divisors is an integer number (55567139482).

Almost surely, 2^221220121123 is an apocalyptic number.

221220121123 is a deficient number, since it is larger than the sum of its proper divisors (1048436805).

221220121123 is a wasteful number, since it uses less digits than its factorization.

221220121123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048436804.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 221220121123 its reverse (321121022122), we get a palindrome (542341143245).

Subtracting 221220121123 from its reverse (321121022122), we obtain a palindrome (99900900999).

The spelling of 221220121123 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, one hundred twenty-three".