66728678 has 16 divisors (see below), whose sum is σ = 103731840. Its totient is φ = 32160000.

The previous prime is 66728677. The next prime is 66728687. The reversal of 66728678 is 87682766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66728677) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14678 + ... + 18678.

It is an arithmetic number, because the mean of its divisors is an integer number (6483240).

Almost surely, 2^66728678 is an apocalyptic number.

66728678 is a deficient number, since it is larger than the sum of its proper divisors (37003162).

66728678 is a wasteful number, since it uses less digits than its factorization.

66728678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4303.

The product of its digits is 1354752, while the sum is 50.

The square root of 66728678 is about 8168.7623297535. The cubic root of 66728678 is about 405.6058158959.

The spelling of 66728678 in words is "sixty-six million, seven hundred twenty-eight thousand, six hundred seventy-eight".