21112102005 has 8 divisors (see below), whose sum is σ = 33779363232. Its totient is φ = 11259787728.

The previous prime is 21112101953. The next prime is 21112102007. The reversal of 21112102005 is 50020121112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21112102005 - 2⁸ = 21112101749 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 1407473467 = 21112102005 / (2 + 1 + 1 + 1 + 2 + 1 + 0 + 2 + 0 + 0 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112102007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 703736719 + ... + 703736748.

It is an arithmetic number, because the mean of its divisors is an integer number (4222420404).

Almost surely, 2^21112102005 is an apocalyptic number.

It is an amenable number.

21112102005 is a deficient number, since it is larger than the sum of its proper divisors (12667261227).

21112102005 is a wasteful number, since it uses less digits than its factorization.

21112102005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407473475.

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

Adding to 21112102005 its reverse (50020121112), we get a palindrome (71132223117).

The spelling of 21112102005 in words is "twenty-one billion, one hundred twelve million, one hundred two thousand, five".