21101011011011 has 4 divisors (see below), whose sum is σ = 21101082982224. Its totient is φ = 21100939039800.

The previous prime is 21101011011007. The next prime is 21101011011023. The reversal of 21101011011011 is 11011011010112.

It is a happy number.

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 21101011011011 - 2² = 21101011011007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101011010983 and 21101011011001.

It is not an unprimeable number, because it can be changed into a prime (21101011011001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35544020 + ... + 36132801.

It is an arithmetic number, because the mean of its divisors is an integer number (5275270745556).

Almost surely, 2^{21101011011011} is an apocalyptic number.

21101011011011 is a deficient number, since it is larger than the sum of its proper divisors (71971213).

21101011011011 is an equidigital number, since it uses as much as digits as its factorization.

21101011011011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71971212.

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 21101011011011 its reverse (11011011010112), we get a palindrome (32112022021123).

The spelling of 21101011011011 in words is "twenty-one trillion, one hundred one billion, eleven million, eleven thousand, eleven".