6561602215664 has 20 divisors (see below), whose sum is σ = 12766297205280. Its totient is φ = 3267073904640.

The previous prime is 6561602215543. The next prime is 6561602215681. The reversal of 6561602215664 is 4665122061656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 857946257 + ... + 857953904.

It is an arithmetic number, because the mean of its divisors is an integer number (638314860264).

Almost surely, 2^{6561602215664} is an apocalyptic number.

It is an amenable number.

6561602215664 is a deficient number, since it is larger than the sum of its proper divisors (6204694989616).

6561602215664 is a wasteful number, since it uses less digits than its factorization.

6561602215664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715900408 (or 1715900402 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 50.

The spelling of 6561602215664 in words is "six trillion, five hundred sixty-one billion, six hundred two million, two hundred fifteen thousand, six hundred sixty-four".