21211011011 has 4 divisors (see below), whose sum is σ = 21211551000. Its totient is φ = 21210471024.

The previous prime is 21211010983. The next prime is 21211011013. The reversal of 21211011011 is 11011011212.

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 21211011011 - 2¹⁴ = 21210994627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211010983 and 21211011001.

It is not an unprimeable number, because it can be changed into a prime (21211011013) 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, 206021 + ... + 291318.

It is an arithmetic number, because the mean of its divisors is an integer number (5302887750).

Almost surely, 2^21211011011 is an apocalyptic number.

21211011011 is a deficient number, since it is larger than the sum of its proper divisors (539989).

21211011011 is an equidigital number, since it uses as much as digits as its factorization.

21211011011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539988.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21211011011 its reverse (11011011212), we get a palindrome (32222022223).

It can be divided in two parts, 212 and 11011011, that multiplied together give a palindrome (2334334332).

The spelling of 21211011011 in words is "twenty-one billion, two hundred eleven million, eleven thousand, eleven".