6561652505 has 16 divisors (see below), whose sum is σ = 8117447184. Its totient is φ = 5088645120.

The previous prime is 6561652501. The next prime is 6561652519. The reversal of 6561652505 is 5052561656.

It can be written as a sum of positive squares in 8 ways, for example, as 790059664 + 5771592841 = 28108^2 + 75971^2 .

It is not a de Polignac number, because 6561652505 - 2² = 6561652501 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6561652501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69752 + ... + 134121.

It is an arithmetic number, because the mean of its divisors is an integer number (507340449).

Almost surely, 2^6561652505 is an apocalyptic number.

It is an amenable number.

6561652505 is a deficient number, since it is larger than the sum of its proper divisors (1555794679).

6561652505 is a wasteful number, since it uses less digits than its factorization.

6561652505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204076.

The product of its (nonzero) digits is 270000, while the sum is 41.

The square root of 6561652505 is about 81004.0277085035. The cubic root of 6561652505 is about 1872.1374992791.

The spelling of 6561652505 in words is "six billion, five hundred sixty-one million, six hundred fifty-two thousand, five hundred five".