21101102205 has 16 divisors (see below), whose sum is σ = 33785066304. Its totient is φ = 11246153600.

The previous prime is 21101102203. The next prime is 21101102207. The reversal of 21101102205 is 50220110112.

It is an interprime number because it is at equal distance from previous prime (21101102203) and next prime (21101102207).

It is not a de Polignac number, because 21101102205 - 2¹ = 21101102203 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101102203) 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 15 ways as a sum of consecutive naturals, for example, 462984 + ... + 506513.

It is an arithmetic number, because the mean of its divisors is an integer number (2111566644).

Almost surely, 2^21101102205 is an apocalyptic number.

It is an amenable number.

21101102205 is a deficient number, since it is larger than the sum of its proper divisors (12683964099).

21101102205 is a wasteful number, since it uses less digits than its factorization.

21101102205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 970956.

The product of its (nonzero) digits is 40, while the sum is 15.

Adding to 21101102205 its reverse (50220110112), we get a palindrome (71321212317).

The spelling of 21101102205 in words is "twenty-one billion, one hundred one million, one hundred two thousand, two hundred five".