6665556564 has 36 divisors (see below), whose sum is σ = 16882194420. Its totient is φ = 2217480960.

The previous prime is 6665556563. The next prime is 6665556619. The reversal of 6665556564 is 4656555666.

It can be written as a sum of positive squares in 2 ways, for example, as 4775915664 + 1889640900 = 69108^2 + 43470^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 6665556564.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665556563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163557 + ... + 200204.

It is an arithmetic number, because the mean of its divisors is an integer number (468949845).

Almost surely, 2^6665556564 is an apocalyptic number.

It is an amenable number.

6665556564 is an abundant number, since it is smaller than the sum of its proper divisors (10216637856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6665556564 is a wasteful number, since it uses less digits than its factorization.

6665556564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364280 (or 364275 counting only the distinct ones).

The product of its digits is 19440000, while the sum is 54.

The square root of 6665556564 is about 81642.8598470191. The cubic root of 6665556564 is about 1881.9675873027.

The spelling of 6665556564 in words is "six billion, six hundred sixty-five million, five hundred fifty-six thousand, five hundred sixty-four".