63866728 has 8 divisors (see below), whose sum is σ = 119750130. Its totient is φ = 31933360.

The previous prime is 63866723. The next prime is 63866741. The reversal of 63866728 is 82766836.

It can be written as a sum of positive squares in only one way, i.e., 61183684 + 2683044 = 7822^2 + 1638^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (63866723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3991663 + ... + 3991678.

Almost surely, 2^63866728 is an apocalyptic number.

It is an amenable number.

63866728 is a deficient number, since it is larger than the sum of its proper divisors (55883402).

63866728 is a wasteful number, since it uses less digits than its factorization.

63866728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7983347 (or 7983343 counting only the distinct ones).

The product of its digits is 580608, while the sum is 46.

The square root of 63866728 is about 7991.6661591936. Note that the first 3 decimals coincide. The cubic root of 63866728 is about 399.7221570529.

The spelling of 63866728 in words is "sixty-three million, eight hundred sixty-six thousand, seven hundred twenty-eight".