221201212220 has 24 divisors (see below), whose sum is σ = 464874245808. Its totient is φ = 88413494400.

The previous prime is 221201212189. The next prime is 221201212247. The reversal of 221201212220 is 22212102122.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4159826 + ... + 4212665.

It is an arithmetic number, because the mean of its divisors is an integer number (19369760242).

Almost surely, 2^221201212220 is an apocalyptic number.

221201212220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221201212220 is an abundant number, since it is smaller than the sum of its proper divisors (243673033588).

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

221201212220 is a wasteful number, since it uses less digits than its factorization.

221201212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8373821 (or 8373819 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221201212220 its reverse (22212102122), we get a palindrome (243413314342).

The spelling of 221201212220 in words is "two hundred twenty-one billion, two hundred one million, two hundred twelve thousand, two hundred twenty".