221101212211220 has 96 divisors (see below), whose sum is σ = 510527813160960. Its totient is φ = 79764762147840.

The previous prime is 221101212211213. The next prime is 221101212211241. The reversal of 221101212211220 is 22112212101122.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 221101212211192 and 221101212211201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 992010032 + ... + 992232888.

It is an arithmetic number, because the mean of its divisors is an integer number (5317998053760).

Almost surely, 2^{221101212211220} is an apocalyptic number.

221101212211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221101212211220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255263906580480).

221101212211220 is an abundant number, since it is smaller than the sum of its proper divisors (289426600949740).

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

221101212211220 is a wasteful number, since it uses less digits than its factorization.

221101212211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258513 (or 258511 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 221101212211220 its reverse (22112212101122), we get a palindrome (243213424312342).

The spelling of 221101212211220 in words is "two hundred twenty-one trillion, one hundred one billion, two hundred twelve million, two hundred eleven thousand, two hundred twenty".