21210111012213 has 20 divisors (see below), whose sum is σ = 31896885830700. Its totient is φ = 14045174174592.

The previous prime is 21210111012173. The next prime is 21210111012221. The reversal of 21210111012213 is 31221011101212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12388302168804 + 8821808843409 = 3519702^2 + 2970153^2 .

It is not a de Polignac number, because 21210111012213 - 2⁹ = 21210111011701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210111019213) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 878690020 + ... + 878714157.

It is an arithmetic number, because the mean of its divisors is an integer number (1594844291535).

Almost surely, 2^{21210111012213} is an apocalyptic number.

It is an amenable number.

21210111012213 is a deficient number, since it is larger than the sum of its proper divisors (10686774818487).

21210111012213 is a wasteful number, since it uses less digits than its factorization.

21210111012213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757404338 (or 1757404329 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 21210111012213 its reverse (31221011101212), we get a palindrome (52431122113425).

The spelling of 21210111012213 in words is "twenty-one trillion, two hundred ten billion, one hundred eleven million, twelve thousand, two hundred thirteen".