100111212121221 has 24 divisors (see below), whose sum is σ = 165463758961280. Its totient is φ = 57136897289376.

The previous prime is 100111212121177. The next prime is 100111212121231. The reversal of 100111212121221 is 122121212111001.

It is a happy number.

100111212121221 is a `hidden beast` number, since 1 + 0 + 0 + 111 + 212 + 121 + 221 = 666.

It is not a de Polignac number, because 100111212121221 - 2⁷ = 100111212121093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100111212121194 and 100111212121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100111212121231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 965359366 + ... + 965463063.

Almost surely, 2^{100111212121221} is an apocalyptic number.

It is an amenable number.

100111212121221 is a deficient number, since it is larger than the sum of its proper divisors (65352546840059).

100111212121221 is a wasteful number, since it uses less digits than its factorization.

100111212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930823265 (or 1930823262 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 100111212121221 its reverse (122121212111001), we get a palindrome (222232424232222).

The spelling of 100111212121221 in words is "one hundred trillion, one hundred eleven billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".