21211102122121 has 4 divisors (see below), whose sum is σ = 21527685735952. Its totient is φ = 20894518508292.

The previous prime is 21211102122107. The next prime is 21211102122169. The reversal of 21211102122121 is 12122120111212.

It is a happy number.

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 21211102122121 - 2¹¹ = 21211102120073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211102122181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158291806815 + ... + 158291806948.

It is an arithmetic number, because the mean of its divisors is an integer number (5381921433988).

Almost surely, 2^{21211102122121} is an apocalyptic number.

It is an amenable number.

21211102122121 is a deficient number, since it is larger than the sum of its proper divisors (316583613831).

21211102122121 is an equidigital number, since it uses as much as digits as its factorization.

21211102122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316583613830.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21211102122121 its reverse (12122120111212), we get a palindrome (33333222233333).

The spelling of 21211102122121 in words is "twenty-one trillion, two hundred eleven billion, one hundred two million, one hundred twenty-two thousand, one hundred twenty-one".