221212120100 has 36 divisors (see below), whose sum is σ = 482712073200. Its totient is φ = 87990512160.

The previous prime is 221212120069. The next prime is 221212120109. The reversal of 221212120100 is 1021212122.

It is not an unprimeable number, because it can be changed into a prime (221212120109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6161210 + ... + 6197009.

It is an arithmetic number, because the mean of its divisors is an integer number (13408668700).

Almost surely, 2^221212120100 is an apocalyptic number.

221212120100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221212120100 is an abundant number, since it is smaller than the sum of its proper divisors (261499953100).

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

221212120100 is a wasteful number, since it uses less digits than its factorization.

221212120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12358412 (or 12358405 counting only the distinct ones).

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

Adding to 221212120100 its reverse (1021212122), we get a palindrome (222233332222).

The spelling of 221212120100 in words is "two hundred twenty-one billion, two hundred twelve million, one hundred twenty thousand, one hundred".