21111021011011 has 4 divisors (see below), whose sum is σ = 21838987252800. Its totient is φ = 20383054769224.

The previous prime is 21111021010987. The next prime is 21111021011039. The reversal of 21111021011011 is 11011012011112.

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 21111021011011 - 2⁵ = 21111021010979 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111021010982 and 21111021011000.

It is not an unprimeable number, because it can be changed into a prime (21111021015011) 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, 363983120851 + ... + 363983120908.

It is an arithmetic number, because the mean of its divisors is an integer number (5459746813200).

Almost surely, 2^{21111021011011} is an apocalyptic number.

21111021011011 is a deficient number, since it is larger than the sum of its proper divisors (727966241789).

21111021011011 is an equidigital number, since it uses as much as digits as its factorization.

21111021011011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727966241788.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21111021011011 its reverse (11011012011112), we get a palindrome (32122033022123).

The spelling of 21111021011011 in words is "twenty-one trillion, one hundred eleven billion, twenty-one million, eleven thousand, eleven".