6561006506 has 4 divisors (see below), whose sum is σ = 9841509762. Its totient is φ = 3280503252.

The previous prime is 6561006499. The next prime is 6561006539. The reversal of 6561006506 is 6056001656.

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

It can be written as a sum of positive squares in only one way, i.e., 3789510481 + 2771496025 = 61559^2 + 52645^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1640251625 + ... + 1640251628.

Almost surely, 2^6561006506 is an apocalyptic number.

6561006506 is a deficient number, since it is larger than the sum of its proper divisors (3280503256).

6561006506 is a wasteful number, since it uses less digits than its factorization.

6561006506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3280503255.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 6561006506 is about 81000.0401604839. The cubic root of 6561006506 is about 1872.0760595405.

The spelling of 6561006506 in words is "six billion, five hundred sixty-one million, six thousand, five hundred six".