221212021100 has 144 divisors (see below), whose sum is σ = 554924190912. Its totient is φ = 74972528640.

The previous prime is 221212021087. The next prime is 221212021117. The reversal of 221212021100 is 1120212122.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 82632962 + ... + 82635638.

Almost surely, 2^221212021100 is an apocalyptic number.

221212021100 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 221212021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277462095456).

221212021100 is an abundant number, since it is smaller than the sum of its proper divisors (333712169812).

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

221212021100 is a wasteful number, since it uses less digits than its factorization.

221212021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4012 (or 4005 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221212021100 its reverse (1120212122), we get a palindrome (222332233222).

The spelling of 221212021100 in words is "two hundred twenty-one billion, two hundred twelve million, twenty-one thousand, one hundred".