2101212112221 has 32 divisors (see below), whose sum is σ = 3129480247680. Its totient is φ = 1393361336448.

The previous prime is 2101212112217. The next prime is 2101212112229. The reversal of 2101212112221 is 1222112121012.

2101212112221 is a `hidden beast` number, since 210 + 1 + 21 + 211 + 2 + 221 = 666.

It is not a de Polignac number, because 2101212112221 - 2² = 2101212112217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2101212112194 and 2101212112203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101212112229) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 6567255 + ... + 6879771.

It is an arithmetic number, because the mean of its divisors is an integer number (97796257740).

Almost surely, 2^{2101212112221} is an apocalyptic number.

It is an amenable number.

2101212112221 is a deficient number, since it is larger than the sum of its proper divisors (1028268135459).

2101212112221 is a wasteful number, since it uses less digits than its factorization.

2101212112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313850 (or 313844 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 2101212112221 its reverse (1222112121012), we get a palindrome (3323324233233).

The spelling of 2101212112221 in words is "two trillion, one hundred one billion, two hundred twelve million, one hundred twelve thousand, two hundred twenty-one".