21131121132113 has 4 divisors (see below), whose sum is σ = 21702232514100. Its totient is φ = 20560009750128.

The previous prime is 21131121132101. The next prime is 21131121132131. The reversal of 21131121132113 is 31123112113112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19583527907584 + 1547593224529 = 4425328^2 + 1244023^2 .

It is a cyclic number.

It is not a de Polignac number, because 21131121132113 - 2²⁴ = 21131104354897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131121162113) 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, 285555690938 + ... + 285555691011.

It is an arithmetic number, because the mean of its divisors is an integer number (5425558128525).

Almost surely, 2^{21131121132113} is an apocalyptic number.

It is an amenable number.

21131121132113 is a deficient number, since it is larger than the sum of its proper divisors (571111381987).

21131121132113 is an equidigital number, since it uses as much as digits as its factorization.

21131121132113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571111381986.

The product of its digits is 216, while the sum is 23.

Adding to 21131121132113 its reverse (31123112113112), we get a palindrome (52254233245225).

The spelling of 21131121132113 in words is "twenty-one trillion, one hundred thirty-one billion, one hundred twenty-one million, one hundred thirty-two thousand, one hundred thirteen".