21100220102121 has 4 divisors (see below), whose sum is σ = 28133626802832. Its totient is φ = 14066813401412.

The previous prime is 21100220102113. The next prime is 21100220102123. The reversal of 21100220102121 is 12120102200112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21100220102121 - 2³ = 21100220102113 is a prime.

It is a super-2 number, since 2×21100220102121² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21100220102121.

It is not an unprimeable number, because it can be changed into a prime (21100220102123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3516703350351 + ... + 3516703350356.

It is an arithmetic number, because the mean of its divisors is an integer number (7033406700708).

Almost surely, 2^{21100220102121} is an apocalyptic number.

It is an amenable number.

21100220102121 is a deficient number, since it is larger than the sum of its proper divisors (7033406700711).

21100220102121 is an equidigital number, since it uses as much as digits as its factorization.

21100220102121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7033406700710.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21100220102121 its reverse (12120102200112), we get a palindrome (33220322302233).

The spelling of 21100220102121 in words is "twenty-one trillion, one hundred billion, two hundred twenty million, one hundred two thousand, one hundred twenty-one".