21100002101 has 4 divisors (see below), whose sum is σ = 21148732332. Its totient is φ = 21051271872.

The previous prime is 21100002083. The next prime is 21100002103. The reversal of 21100002101 is 10120000112.

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 8949349201 + 12150652900 = 94601^2 + 110230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21100002101 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 (21100002103) 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, 24364466 + ... + 24365331.

It is an arithmetic number, because the mean of its divisors is an integer number (5287183083).

Almost surely, 2^21100002101 is an apocalyptic number.

It is an amenable number.

21100002101 is a deficient number, since it is larger than the sum of its proper divisors (48730231).

21100002101 is an equidigital number, since it uses as much as digits as its factorization.

21100002101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48730230.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21100002101 its reverse (10120000112), we get a palindrome (31220002213).

The spelling of 21100002101 in words is "twenty-one billion, one hundred million, two thousand, one hundred one".