21311310031313 has 4 divisors (see below), whose sum is σ = 21311862133488. Its totient is φ = 21310757929140.

The previous prime is 21311310031301. The next prime is 21311310031331. The reversal of 21311310031313 is 31313001311312.

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 a de Polignac number, because none of the positive numbers 2^k-21311310031313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311310031343) 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, 275993183 + ... + 276070388.

It is an arithmetic number, because the mean of its divisors is an integer number (5327965533372).

Almost surely, 2^{21311310031313} is an apocalyptic number.

It is an amenable number.

21311310031313 is a deficient number, since it is larger than the sum of its proper divisors (552102175).

21311310031313 is an equidigital number, since it uses as much as digits as its factorization.

21311310031313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552102174.

The product of its (nonzero) digits is 486, while the sum is 23.

Adding to 21311310031313 its reverse (31313001311312), we get a palindrome (52624311342625).

The spelling of 21311310031313 in words is "twenty-one trillion, three hundred eleven billion, three hundred ten million, thirty-one thousand, three hundred thirteen".