6663206556 has 96 divisors (see below), whose sum is σ = 17723059200. Its totient is φ = 2163732480.

The previous prime is 6663206519. The next prime is 6663206611. The reversal of 6663206556 is 6556023666.

It is a super-2 number, since 2×6663206556² = 88796643215842762272, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1999900 + ... + 2003228.

It is an arithmetic number, because the mean of its divisors is an integer number (184615200).

Almost surely, 2^6663206556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6663206556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8861529600).

6663206556 is an abundant number, since it is smaller than the sum of its proper divisors (11059852644).

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

6663206556 is a wasteful number, since it uses less digits than its factorization.

6663206556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3816 (or 3808 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 45.

The square root of 6663206556 is about 81628.4665787616. The cubic root of 6663206556 is about 1881.7463925335.

The spelling of 6663206556 in words is "six billion, six hundred sixty-three million, two hundred six thousand, five hundred fifty-six".