10211211221 has 4 divisors (see below), whose sum is σ = 10212040812. Its totient is φ = 10210381632.

The previous prime is 10211211191. The next prime is 10211211259. The reversal of 10211211221 is 12211211201.

10211211221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12211211201 = 7 ⋅1744458743.

It can be written as a sum of positive squares in 2 ways, for example, as 4397148721 + 5814062500 = 66311^2 + 76250^2 .

It is a cyclic number.

It is not a de Polignac number, because 10211211221 - 2¹⁴ = 10211194837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10211211196 and 10211211205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10211211821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396050 + ... + 421043.

It is an arithmetic number, because the mean of its divisors is an integer number (2553010203).

Almost surely, 2^10211211221 is an apocalyptic number.

It is an amenable number.

10211211221 is a deficient number, since it is larger than the sum of its proper divisors (829591).

10211211221 is an equidigital number, since it uses as much as digits as its factorization.

10211211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829590.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 10211211221 its reverse (12211211201), we get a palindrome (22422422422).

The spelling of 10211211221 in words is "ten billion, two hundred eleven million, two hundred eleven thousand, two hundred twenty-one".