20121222220100 has 108 divisors (see below), whose sum is σ = 45649255927296. Its totient is φ = 7697665546560.

The previous prime is 20121222220069. The next prime is 20121222220201. The reversal of 20121222220100 is 102222212102.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 627536669 + ... + 627568731.

Almost surely, 2^{20121222220100} is an apocalyptic number.

20121222220100 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 20121222220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22824627963648).

20121222220100 is an abundant number, since it is smaller than the sum of its proper divisors (25528033707196).

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

20121222220100 is a wasteful number, since it uses less digits than its factorization.

20121222220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43986 (or 43956 counting only the distinct ones).

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

Adding to 20121222220100 its reverse (102222212102), we get a palindrome (20223444432202).

The spelling of 20121222220100 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-two million, two hundred twenty thousand, one hundred".