66725666 has 16 divisors (see below), whose sum is σ = 115499904. Its totient is φ = 28318464.

The previous prime is 66725639. The next prime is 66725677. The reversal of 66725666 is 66652766.

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, 21695 + ... + 24578.

It is an arithmetic number, because the mean of its divisors is an integer number (7218744).

Almost surely, 2^66725666 is an apocalyptic number.

66725666 is a deficient number, since it is larger than the sum of its proper divisors (48774238).

66725666 is a wasteful number, since it uses less digits than its factorization.

66725666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46385.

The product of its digits is 544320, while the sum is 44.

The square root of 66725666 is about 8168.5779668189. The cubic root of 66725666 is about 405.5997130571.

Subtracting from 66725666 its reverse (66652766), we obtain a square (72900 = 270²).

The spelling of 66725666 in words is "sixty-six million, seven hundred twenty-five thousand, six hundred sixty-six".