221212210100 has 216 divisors, whose sum is σ = 590630634720. Its totient is φ = 71505504000.

The previous prime is 221212210067. The next prime is 221212210103. The reversal of 221212210100 is 1012212122.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212210103) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 19638470 + ... + 19649730.

Almost surely, 2^221212210100 is an apocalyptic number.

221212210100 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 221212210100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295315317360).

221212210100 is an abundant number, since it is smaller than the sum of its proper divisors (369418424620).

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

221212210100 is a wasteful number, since it uses less digits than its factorization.

221212210100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11519 (or 11505 counting only the distinct ones).

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

Adding to 221212210100 its reverse (1012212122), we get a palindrome (222224422222).

It can be divided in two parts, 2212122 and 10100, that added together give a palindrome (2222222).

The spelling of 221212210100 in words is "two hundred twenty-one billion, two hundred twelve million, two hundred ten thousand, one hundred".