66563968 has 16 divisors (see below), whose sum is σ = 132608160. Its totient is φ = 33281920.

The previous prime is 66563953. The next prime is 66563989. The reversal of 66563968 is 86936566.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259888 + ... + 260143.

It is an arithmetic number, because the mean of its divisors is an integer number (8288010).

Almost surely, 2^66563968 is an apocalyptic number.

It is an amenable number.

66563968 is a deficient number, since it is larger than the sum of its proper divisors (66044192).

66563968 is an equidigital number, since it uses as much as digits as its factorization.

66563968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520045 (or 520033 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 49.

The square root of 66563968 is about 8158.6744021318. The cubic root of 66563968 is about 405.2718146864.

The spelling of 66563968 in words is "sixty-six million, five hundred sixty-three thousand, nine hundred sixty-eight".