221211111011220 has 72 divisors (see below), whose sum is σ = 732007676443680. Its totient is φ = 53626936002240.

The previous prime is 221211111011201. The next prime is 221211111011249. The reversal of 221211111011220 is 22110111112122.

It is a happy number.

221211111011220 is a `hidden beast` number, since 2 + 212 + 111 + 110 + 11 + 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 = 221211111011193 and 221211111011202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 55861389690 + ... + 55861393649.

It is an arithmetic number, because the mean of its divisors is an integer number (10166773283940).

Almost surely, 2^{221211111011220} is an apocalyptic number.

221211111011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221211111011220 is an abundant number, since it is smaller than the sum of its proper divisors (510796565432460).

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

221211111011220 is a wasteful number, since it uses less digits than its factorization.

221211111011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111722783365 (or 111722783360 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 221211111011220 its reverse (22110111112122), we get a palindrome (243321222123342).

The spelling of 221211111011220 in words is "two hundred twenty-one trillion, two hundred eleven billion, one hundred eleven million, eleven thousand, two hundred twenty".