21011103101 has 4 divisors (see below), whose sum is σ = 21013715100. Its totient is φ = 21008491104.

The previous prime is 21011103073. The next prime is 21011103107. The reversal of 21011103101 is 10130111012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6388005625 + 14623097476 = 79925^2 + 120926^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011103101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011103107) 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 3 ways as a sum of consecutive naturals, for example, 1293896 + ... + 1310033.

It is an arithmetic number, because the mean of its divisors is an integer number (5253428775).

Almost surely, 2^21011103101 is an apocalyptic number.

It is an amenable number.

21011103101 is a deficient number, since it is larger than the sum of its proper divisors (2611999).

21011103101 is an equidigital number, since it uses as much as digits as its factorization.

21011103101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2611998.

The product of its (nonzero) digits is 6, while the sum is 11.

Adding to 21011103101 its reverse (10130111012), we get a palindrome (31141214113).

The spelling of 21011103101 in words is "twenty-one billion, eleven million, one hundred three thousand, one hundred one".