21100002120105 has 16 divisors (see below), whose sum is σ = 33765518978304. Its totient is φ = 11251495935360.

The previous prime is 21100002120101. The next prime is 21100002120107. The reversal of 21100002120105 is 50102120000112.

It is not a de Polignac number, because 21100002120105 - 2² = 21100002120101 is a prime.

It is a super-2 number, since 2×21100002120105² (a number of 27 digits) contains 22 as substring.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21100002120101) 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, 114813169 + ... + 114996798.

It is an arithmetic number, because the mean of its divisors is an integer number (2110344936144).

Almost surely, 2^{21100002120105} is an apocalyptic number.

It is an amenable number.

21100002120105 is a deficient number, since it is larger than the sum of its proper divisors (12665516858199).

21100002120105 is a wasteful number, since it uses less digits than its factorization.

21100002120105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229816096.

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

Adding to 21100002120105 its reverse (50102120000112), we get a palindrome (71202122120217).

The spelling of 21100002120105 in words is "twenty-one trillion, one hundred billion, two million, one hundred twenty thousand, one hundred five".