66963728 has 40 divisors (see below), whose sum is σ = 142990848. Its totient is φ = 30183552.

The previous prime is 66963719. The next prime is 66963739. The reversal of 66963728 is 82736966.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5201 + ... + 12687.

Almost surely, 2^66963728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66963728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71495424).

66963728 is an abundant number, since it is smaller than the sum of its proper divisors (76027120).

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

66963728 is a wasteful number, since it uses less digits than its factorization.

66963728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7551 (or 7545 counting only the distinct ones).

The product of its digits is 653184, while the sum is 47.

The square root of 66963728 is about 8183.1368068730. The cubic root of 66963728 is about 406.0815030467.

The spelling of 66963728 in words is "sixty-six million, nine hundred sixty-three thousand, seven hundred twenty-eight".