21211002011 has 4 divisors (see below), whose sum is σ = 21258243000. Its totient is φ = 21163761024.

The previous prime is 21211001993. The next prime is 21211002037. The reversal of 21211002011 is 11020011212.

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 21211002011 - 2³⁴ = 4031132827 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211001983 and 21211002001.

It is not an unprimeable number, because it can be changed into a prime (21211002511) 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, 23619821 + ... + 23620718.

It is an arithmetic number, because the mean of its divisors is an integer number (5314560750).

Almost surely, 2^21211002011 is an apocalyptic number.

21211002011 is a deficient number, since it is larger than the sum of its proper divisors (47240989).

21211002011 is an equidigital number, since it uses as much as digits as its factorization.

21211002011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47240988.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21211002011 its reverse (11020011212), we get a palindrome (32231013223).

The spelling of 21211002011 in words is "twenty-one billion, two hundred eleven million, two thousand, eleven".