6531509913 has 16 divisors (see below), whose sum is σ = 8910888000. Its totient is φ = 4254194880.

The previous prime is 6531509911. The next prime is 6531509923. The reversal of 6531509913 is 3199051356.

It is not a de Polignac number, because 6531509913 - 2¹ = 6531509911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6531509911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92503 + ... + 147036.

It is an arithmetic number, because the mean of its divisors is an integer number (556930500).

Almost surely, 2^6531509913 is an apocalyptic number.

It is an amenable number.

6531509913 is a deficient number, since it is larger than the sum of its proper divisors (2379378087).

6531509913 is a wasteful number, since it uses less digits than its factorization.

6531509913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239752.

The product of its (nonzero) digits is 109350, while the sum is 42.

The square root of 6531509913 is about 80817.7574113511. The cubic root of 6531509913 is about 1869.2663877688.

The spelling of 6531509913 in words is "six billion, five hundred thirty-one million, five hundred nine thousand, nine hundred thirteen".