21000110011 has 4 divisors (see below), whose sum is σ = 21014215000. Its totient is φ = 20986005024.

The previous prime is 21000109937. The next prime is 21000110029. The reversal of 21000110011 is 11001100012.

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 21000110011 - 2¹¹ = 21000107963 is a prime.

It is a Duffinian number.

21000110011 is a modest number, since divided by 110011 gives 210 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21000109976 and 21000110003.

It is not an unprimeable number, because it can be changed into a prime (21000110041) 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, 7050261 + ... + 7053238.

It is an arithmetic number, because the mean of its divisors is an integer number (5253553750).

Almost surely, 2^21000110011 is an apocalyptic number.

21000110011 is a deficient number, since it is larger than the sum of its proper divisors (14104989).

21000110011 is a wasteful number, since it uses less digits than its factorization.

21000110011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14104988.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21000110011 its reverse (11001100012), we get a palindrome (32001210023).

Subtracting from 21000110011 its reverse (11001100012), we obtain a palindrome (9999009999).

The spelling of 21000110011 in words is "twenty-one billion, one hundred ten thousand, eleven".