6561006616 has 8 divisors (see below), whose sum is σ = 12301887420. Its totient is φ = 3280503304.

The previous prime is 6561006601. The next prime is 6561006623. The reversal of 6561006616 is 6166001656.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410062906 + ... + 410062921.

Almost surely, 2^6561006616 is an apocalyptic number.

It is an amenable number.

6561006616 is a deficient number, since it is larger than the sum of its proper divisors (5740880804).

6561006616 is a wasteful number, since it uses less digits than its factorization.

6561006616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820125833 (or 820125829 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 6561006616 is about 81000.0408394959. The cubic root of 6561006616 is about 1872.0760700028.

The spelling of 6561006616 in words is "six billion, five hundred sixty-one million, six thousand, six hundred sixteen".