6438720013 has 4 divisors (see below), whose sum is σ = 7024058208. Its totient is φ = 5853381820.

The previous prime is 6438720011. The next prime is 6438720031. The reversal of 6438720013 is 3100278346.

It is a happy number.

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 6438720013 - 2¹ = 6438720011 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 (6438720011) 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, 292669081 + ... + 292669102.

It is an arithmetic number, because the mean of its divisors is an integer number (1756014552).

Almost surely, 2^6438720013 is an apocalyptic number.

It is an amenable number.

6438720013 is a deficient number, since it is larger than the sum of its proper divisors (585338195).

6438720013 is a wasteful number, since it uses less digits than its factorization.

6438720013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585338194.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 6438720013 is about 80241.6351590619. The cubic root of 6438720013 is about 1860.3722241333.

Adding to 6438720013 its reverse (3100278346), we get a palindrome (9538998359).

The spelling of 6438720013 in words is "six billion, four hundred thirty-eight million, seven hundred twenty thousand, thirteen".