221111231220 has 96 divisors (see below), whose sum is σ = 750438138240. Its totient is φ = 53602721280.

The previous prime is 221111231189. The next prime is 221111231227. The reversal of 221111231220 is 22132111122.

221111231220 is a `hidden beast` number, since 2 + 211 + 1 + 1 + 231 + 220 = 666.

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 = 221111231193 and 221111231202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111231227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18606117 + ... + 18617996.

It is an arithmetic number, because the mean of its divisors is an integer number (7817063940).

Almost surely, 2^221111231220 is an apocalyptic number.

221111231220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221111231220 is an abundant number, since it is smaller than the sum of its proper divisors (529326907020).

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

221111231220 is a wasteful number, since it uses less digits than its factorization.

221111231220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37224142 (or 37224134 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 221111231220 its reverse (22132111122), we get a palindrome (243243342342).

The spelling of 221111231220 in words is "two hundred twenty-one billion, one hundred eleven million, two hundred thirty-one thousand, two hundred twenty".