6663656406 has 16 divisors (see below), whose sum is σ = 14538886848. Its totient is φ = 2019289800.

The previous prime is 6663656359. The next prime is 6663656407. The reversal of 6663656406 is 6046563666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6663656407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50482180 + ... + 50482311.

It is an arithmetic number, because the mean of its divisors is an integer number (908680428).

Almost surely, 2^6663656406 is an apocalyptic number.

6663656406 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6663656406 is an abundant number, since it is smaller than the sum of its proper divisors (7875230442).

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

6663656406 is a wasteful number, since it uses less digits than its factorization.

6663656406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100964507.

The product of its (nonzero) digits is 2799360, while the sum is 48.

The square root of 6663656406 is about 81631.2220048187. Note that the first 3 decimals coincide. The cubic root of 6663656406 is about 1881.7887387402.

The spelling of 6663656406 in words is "six billion, six hundred sixty-three million, six hundred fifty-six thousand, four hundred six".