21001102121211 has 16 divisors (see below), whose sum is σ = 28022363596800. Its totient is φ = 13990289089088.

The previous prime is 21001102121161. The next prime is 21001102121239. The reversal of 21001102121211 is 11212120110012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21001102121211 - 2¹¹ = 21001102119163 is a prime.

It is a super-2 number, since 2×21001102121211² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21001102121261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62997055 + ... + 63329543.

It is an arithmetic number, because the mean of its divisors is an integer number (1751397724800).

Almost surely, 2^{21001102121211} is an apocalyptic number.

21001102121211 is a deficient number, since it is larger than the sum of its proper divisors (7021261475589).

21001102121211 is a wasteful number, since it uses less digits than its factorization.

21001102121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348138.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21001102121211 its reverse (11212120110012), we get a palindrome (32213222231223).

The spelling of 21001102121211 in words is "twenty-one trillion, one billion, one hundred two million, one hundred twenty-one thousand, two hundred eleven".