21013311122121 has 4 divisors (see below), whose sum is σ = 28017748162832. Its totient is φ = 14008874081412.

The previous prime is 21013311122119. The next prime is 21013311122143. The reversal of 21013311122121 is 12122111331012.

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 not a de Polignac number, because 21013311122121 - 2¹ = 21013311122119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013311122021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3502218520351 + ... + 3502218520356.

It is an arithmetic number, because the mean of its divisors is an integer number (7004437040708).

Almost surely, 2^{21013311122121} is an apocalyptic number.

It is an amenable number.

21013311122121 is a deficient number, since it is larger than the sum of its proper divisors (7004437040711).

21013311122121 is an equidigital number, since it uses as much as digits as its factorization.

21013311122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7004437040710.

The product of its (nonzero) digits is 144, while the sum is 21.

Adding to 21013311122121 its reverse (12122111331012), we get a palindrome (33135422453133).

The spelling of 21013311122121 in words is "twenty-one trillion, thirteen billion, three hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".