21210100011121 has 4 divisors (see below), whose sum is σ = 24240114298432. Its totient is φ = 18180085723812.

The previous prime is 21210100011103. The next prime is 21210100011157. The reversal of 21210100011121 is 12111000101212.

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 21210100011121 - 2⁹ = 21210100010609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210100011181) 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, 1515007143645 + ... + 1515007143658.

It is an arithmetic number, because the mean of its divisors is an integer number (6060028574608).

Almost surely, 2^{21210100011121} is an apocalyptic number.

It is an amenable number.

21210100011121 is a deficient number, since it is larger than the sum of its proper divisors (3030014287311).

21210100011121 is an equidigital number, since it uses as much as digits as its factorization.

21210100011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030014287310.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21210100011121 its reverse (12111000101212), we get a palindrome (33321100112333).

Subtracting from 21210100011121 its reverse (12111000101212), we obtain a palindrome (9099099909909).

The spelling of 21210100011121 in words is "twenty-one trillion, two hundred ten billion, one hundred million, eleven thousand, one hundred twenty-one".