1221100100212 has 24 divisors (see below), whose sum is σ = 2219381377920. Its totient is φ = 587431488960.

The previous prime is 1221100100189. The next prime is 1221100100243. The reversal of 1221100100212 is 2120010011221.

It is a junction number, because it is equal to n+sod(n) for n = 1221100100192 and 1221100100201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55033089 + ... + 55055272.

It is an arithmetic number, because the mean of its divisors is an integer number (92474224080).

Almost surely, 2^{1221100100212} is an apocalyptic number.

It is an amenable number.

1221100100212 is a deficient number, since it is larger than the sum of its proper divisors (998281277708).

1221100100212 is a wasteful number, since it uses less digits than its factorization.

1221100100212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110088471 (or 110088469 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221100100212 its reverse (2120010011221), we get a palindrome (3341110111433).

The spelling of 1221100100212 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred thousand, two hundred twelve".