6520564667257 has 4 divisors (see below), whose sum is σ = 6520570171216. Its totient is φ = 6520559163300.

The previous prime is 6520564667231. The next prime is 6520564667263. The reversal of 6520564667257 is 7527664650256.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 6520564667257 - 2¹⁵ = 6520564634489 is a prime.

It is a super-2 number, since 2×6520564667257² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6520564667195 and 6520564667204.

It is not an unprimeable number, because it can be changed into a prime (6520564667557) 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, 163119 + ... + 3614932.

It is an arithmetic number, because the mean of its divisors is an integer number (1630142542804).

Almost surely, 2^{6520564667257} is an apocalyptic number.

It is an amenable number.

6520564667257 is a deficient number, since it is larger than the sum of its proper divisors (5503959).

6520564667257 is a wasteful number, since it uses less digits than its factorization.

6520564667257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5503958.

The product of its (nonzero) digits is 127008000, while the sum is 61.

The spelling of 6520564667257 in words is "six trillion, five hundred twenty billion, five hundred sixty-four million, six hundred sixty-seven thousand, two hundred fifty-seven".