21011101100001 has 12 divisors (see below), whose sum is σ = 30503425965012. Its totient is φ = 13936297175136.

The previous prime is 21011101099997. The next prime is 21011101100029. The reversal of 21011101100001 is 10000110111012.

It can be written as a sum of positive squares in 2 ways, for example, as 18691130408976 + 2319970691025 = 4323324^2 + 1523145^2 .

It is not a de Polignac number, because 21011101100001 - 2² = 21011101099997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21011101100501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5925294646 + ... + 5925298191.

It is an arithmetic number, because the mean of its divisors is an integer number (2541952163751).

Almost surely, 2^{21011101100001} is an apocalyptic number.

It is an amenable number.

21011101100001 is a deficient number, since it is larger than the sum of its proper divisors (9492324865011).

21011101100001 is a wasteful number, since it uses less digits than its factorization.

21011101100001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11850593040 (or 11850593037 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 21011101100001 its reverse (10000110111012), we get a palindrome (31011211211013).

The spelling of 21011101100001 in words is "twenty-one trillion, eleven billion, one hundred one million, one hundred thousand, one".