6520813457 has 4 divisors (see below), whose sum is σ = 6588038436. Its totient is φ = 6453588480.

The previous prime is 6520813379. The next prime is 6520813469. The reversal of 6520813457 is 7543180256.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5095675456 + 1425138001 = 71384^2 + 37751^2 .

It is not a de Polignac number, because 6520813457 - 2²⁸ = 6252378001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6520813477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33612344 + ... + 33612537.

It is an arithmetic number, because the mean of its divisors is an integer number (1647009609).

Almost surely, 2^6520813457 is an apocalyptic number.

It is an amenable number.

6520813457 is a deficient number, since it is larger than the sum of its proper divisors (67224979).

6520813457 is an equidigital number, since it uses as much as digits as its factorization.

6520813457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67224978.

The product of its (nonzero) digits is 201600, while the sum is 41.

The square root of 6520813457 is about 80751.5538983616. The cubic root of 6520813457 is about 1868.2454165750.

The spelling of 6520813457 in words is "six billion, five hundred twenty million, eight hundred thirteen thousand, four hundred fifty-seven".