63661921864 has 16 divisors (see below), whose sum is σ = 119376892800. Its totient is φ = 31828083792.

The previous prime is 63661921849. The next prime is 63661921867. The reversal of 63661921864 is 46812916636.

It is a happy number.

63661921864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (63661921867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264112 + ... + 443935.

It is an arithmetic number, because the mean of its divisors is an integer number (7461055800).

Almost surely, 2^63661921864 is an apocalyptic number.

It is an amenable number.

63661921864 is a deficient number, since it is larger than the sum of its proper divisors (55714970936).

63661921864 is a wasteful number, since it uses less digits than its factorization.

63661921864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719292 (or 719288 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 52.

The spelling of 63661921864 in words is "sixty-three billion, six hundred sixty-one million, nine hundred twenty-one thousand, eight hundred sixty-four".