6520078009 has 3 divisors (see below), whose sum is σ = 6520158757. Its totient is φ = 6519997262.

The previous prime is 6520077947. The next prime is 6520078027. The reversal of 6520078009 is 9008700256.

The square root of 6520078009 is 80747.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 6520078009 - 2¹⁹ = 6519553721 is a prime.

It is a super-2 number, since 2×6520078009² = 85022834486890808162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6520078109) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 40374 + ... + 121120.

Almost surely, 2^6520078009 is an apocalyptic number.

6520078009 is the 80747-th square number.

6520078009 is the 40374-th centered octagonal number.

It is an amenable number.

6520078009 is a deficient number, since it is larger than the sum of its proper divisors (80748).

6520078009 is an frugal number, since it uses more digits than its factorization.

6520078009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161494 (or 80747 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 37.

The cubic root of 6520078009 is about 1868.1751774337.

The spelling of 6520078009 in words is "six billion, five hundred twenty million, seventy-eight thousand, nine".