21123303040013 has 4 divisors (see below), whose sum is σ = 21130036643100. Its totient is φ = 21116569436928.

The previous prime is 21123303039959. The next prime is 21123303040027. The reversal of 21123303040013 is 31004030332112.

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 13404224347684 + 7719078692329 = 3661178^2 + 2778323^2 .

It is a cyclic number.

It is not a de Polignac number, because 21123303040013 - 2²⁸ = 21123034604557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123303040513) 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, 3366796838 + ... + 3366803111.

It is an arithmetic number, because the mean of its divisors is an integer number (5282509160775).

Almost surely, 2^{21123303040013} is an apocalyptic number.

It is an amenable number.

21123303040013 is a deficient number, since it is larger than the sum of its proper divisors (6733603087).

21123303040013 is an equidigital number, since it uses as much as digits as its factorization.

21123303040013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6733603086.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21123303040013 its reverse (31004030332112), we get a palindrome (52127333372125).

The spelling of 21123303040013 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred three million, forty thousand, thirteen".