221111120124 has 72 divisors (see below), whose sum is σ = 568222134480. Its totient is φ = 72480748032.

The previous prime is 221111120123. The next prime is 221111120129. The reversal of 221111120124 is 421021111122.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 221111120097 and 221111120106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111120123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1353022 + ... + 1507610.

It is an arithmetic number, because the mean of its divisors is an integer number (7891974090).

Almost surely, 2^221111120124 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221111120124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284111067240).

221111120124 is an abundant number, since it is smaller than the sum of its proper divisors (347111014356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221111120124 is a wasteful number, since it uses less digits than its factorization.

221111120124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155259 (or 155254 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 221111120124 its reverse (421021111122), we get a palindrome (642132231246).

The spelling of 221111120124 in words is "two hundred twenty-one billion, one hundred eleven million, one hundred twenty thousand, one hundred twenty-four".