21001011220105 has 32 divisors (see below), whose sum is σ = 28881300704256. Its totient is φ = 14360740383744.

The previous prime is 21001011220099. The next prime is 21001011220139. The reversal of 21001011220105 is 50102211010012.

It is a cyclic number.

It is not a de Polignac number, because 21001011220105 - 2¹³ = 21001011211913 is a prime.

It is a super-2 number, since 2×21001011220105² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 468781567 + ... + 468826363.

It is an arithmetic number, because the mean of its divisors is an integer number (902540647008).

Almost surely, 2^{21001011220105} is an apocalyptic number.

It is an amenable number.

21001011220105 is a deficient number, since it is larger than the sum of its proper divisors (7880289484151).

21001011220105 is a wasteful number, since it uses less digits than its factorization.

21001011220105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81673.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 21001011220105 its reverse (50102211010012), we get a palindrome (71103222230117).

The spelling of 21001011220105 in words is "twenty-one trillion, one billion, eleven million, two hundred twenty thousand, one hundred five".