6566621565 has 48 divisors (see below), whose sum is σ = 12336328512. Its totient is φ = 2973793536.

The previous prime is 6566621561. The next prime is 6566621573. The reversal of 6566621565 is 5651266656.

It is not a de Polignac number, because 6566621565 - 2² = 6566621561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6566621561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36897 + ... + 120393.

It is an arithmetic number, because the mean of its divisors is an integer number (257006844).

Almost surely, 2^6566621565 is an apocalyptic number.

It is an amenable number.

6566621565 is a deficient number, since it is larger than the sum of its proper divisors (5769706947).

6566621565 is a wasteful number, since it uses less digits than its factorization.

6566621565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83626 (or 83619 counting only the distinct ones).

The product of its digits is 1944000, while the sum is 48.

The square root of 6566621565 is about 81034.6935886106. The cubic root of 6566621565 is about 1872.6099623897.

The spelling of 6566621565 in words is "six billion, five hundred sixty-six million, six hundred twenty-one thousand, five hundred sixty-five".