63666063666 has 96 divisors (see below), whose sum is σ = 145586016576. Its totient is φ = 20849400000.

The previous prime is 63666063649. The next prime is 63666063691. The reversal of 63666063666 is 66636066636.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6425316 + ... + 6435216.

It is an arithmetic number, because the mean of its divisors is an integer number (1516521006).

Almost surely, 2^63666063666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 63666063666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72793008288).

63666063666 is an abundant number, since it is smaller than the sum of its proper divisors (81919952910).

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

63666063666 is a wasteful number, since it uses less digits than its factorization.

63666063666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10150 (or 10138 counting only the distinct ones).

The product of its (nonzero) digits is 15116544, while the sum is 54.

The spelling of 63666063666 in words is "sixty-three billion, six hundred sixty-six million, sixty-three thousand, six hundred sixty-six".