21010212211 has 4 divisors (see below), whose sum is σ = 21687961024. Its totient is φ = 20332463400.

The previous prime is 21010212199. The next prime is 21010212257. The reversal of 21010212211 is 11221201012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21010212211 - 2⁹ = 21010211699 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010212191 and 21010212200.

It is not an unprimeable number, because it can be changed into a prime (21010212281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338874360 + ... + 338874421.

It is an arithmetic number, because the mean of its divisors is an integer number (5421990256).

Almost surely, 2^21010212211 is an apocalyptic number.

21010212211 is a deficient number, since it is larger than the sum of its proper divisors (677748813).

21010212211 is an equidigital number, since it uses as much as digits as its factorization.

21010212211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677748812.

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

Adding to 21010212211 its reverse (11221201012), we get a palindrome (32231413223).

The spelling of 21010212211 in words is "twenty-one billion, ten million, two hundred twelve thousand, two hundred eleven".