6515666505 has 24 divisors (see below), whose sum is σ = 11478971400. Its totient is φ = 3418053120.

The previous prime is 6515666503. The next prime is 6515666519. The reversal of 6515666505 is 5056665156.

It can be written as a sum of positive squares in 4 ways, for example, as 670758201 + 5844908304 = 25899^2 + 76452^2 .

It is not a de Polignac number, because 6515666505 - 2¹ = 6515666503 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (6515666503) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1184080 + ... + 1189569.

It is an arithmetic number, because the mean of its divisors is an integer number (478290475).

Almost surely, 2^6515666505 is an apocalyptic number.

It is an amenable number.

6515666505 is a deficient number, since it is larger than the sum of its proper divisors (4963304895).

6515666505 is a wasteful number, since it uses less digits than its factorization.

6515666505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2373721 (or 2373718 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The square root of 6515666505 is about 80719.6785486662. The cubic root of 6515666505 is about 1867.7537447612.

The spelling of 6515666505 in words is "six billion, five hundred fifteen million, six hundred sixty-six thousand, five hundred five".