210111212011221 has 12 divisors (see below), whose sum is σ = 303748368539148. Its totient is φ = 139956727971264.

The previous prime is 210111212011213. The next prime is 210111212011249. The reversal of 210111212011221 is 122110212111012.

It is a happy number.

210111212011221 is a `hidden beast` number, since 210 + 1 + 11 + 21 + 201 + 1 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 40165807522500 + 169945404488721 = 6337650^2 + 13036311^2 .

It is not a de Polignac number, because 210111212011221 - 2³ = 210111212011213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210111212011194 and 210111212011203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210111212011201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9784436130 + ... + 9784457603.

It is an arithmetic number, because the mean of its divisors is an integer number (25312364044929).

Almost surely, 2^{210111212011221} is an apocalyptic number.

It is an amenable number.

210111212011221 is a deficient number, since it is larger than the sum of its proper divisors (93637156527927).

210111212011221 is a wasteful number, since it uses less digits than its factorization.

210111212011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19568894932 (or 19568894929 counting only the distinct ones).

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

Adding to 210111212011221 its reverse (122110212111012), we get a palindrome (332221424122233).

The spelling of 210111212011221 in words is "two hundred ten trillion, one hundred eleven billion, two hundred twelve million, eleven thousand, two hundred twenty-one".