21010102121105 has 8 divisors (see below), whose sum is σ = 26695188577512. Its totient is φ = 15819371008768.

The previous prime is 21010102121059. The next prime is 21010102121123. The reversal of 21010102121105 is 50112120101012.

It can be written as a sum of positive squares in 4 ways, for example, as 6916752720784 + 14093349400321 = 2629972^2 + 3754111^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21010102121105 - 2³⁰ = 21009028379281 is a prime.

It is a super-2 number, since 2×21010102121105² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 123588835922 + ... + 123588836091.

It is an arithmetic number, because the mean of its divisors is an integer number (3336898572189).

Almost surely, 2^{21010102121105} is an apocalyptic number.

It is an amenable number.

21010102121105 is a deficient number, since it is larger than the sum of its proper divisors (5685086456407).

21010102121105 is a wasteful number, since it uses less digits than its factorization.

21010102121105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247177672035.

The product of its (nonzero) digits is 40, while the sum is 17.

Adding to 21010102121105 its reverse (50112120101012), we get a palindrome (71122222222117).

The spelling of 21010102121105 in words is "twenty-one trillion, ten billion, one hundred two million, one hundred twenty-one thousand, one hundred five".