21310431534013 has 4 divisors (see below), whose sum is σ = 21327041380608. Its totient is φ = 21293821687420.

The previous prime is 21310431534001. The next prime is 21310431534061. The reversal of 21310431534013 is 31043513401312.

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 21310431534013 - 2²¹ = 21310429436861 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 (21310431334013) 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, 8304921373 + ... + 8304923938.

It is an arithmetic number, because the mean of its divisors is an integer number (5331760345152).

Almost surely, 2^{21310431534013} is an apocalyptic number.

It is an amenable number.

21310431534013 is a deficient number, since it is larger than the sum of its proper divisors (16609846595).

21310431534013 is a wasteful number, since it uses less digits than its factorization.

21310431534013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16609846594.

The product of its (nonzero) digits is 12960, while the sum is 31.

Adding to 21310431534013 its reverse (31043513401312), we get a palindrome (52353944935325).

The spelling of 21310431534013 in words is "twenty-one trillion, three hundred ten billion, four hundred thirty-one million, five hundred thirty-four thousand, thirteen".