66400275 has 24 divisors (see below), whose sum is σ = 110015280. Its totient is φ = 35338240.

The previous prime is 66400261. The next prime is 66400277. The reversal of 66400275 is 57200466.

66400275 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66400275 - 2⁴ = 66400259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66400277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69199 + ... + 70151.

It is an arithmetic number, because the mean of its divisors is an integer number (4583970).

Almost surely, 2^66400275 is an apocalyptic number.

66400275 is a deficient number, since it is larger than the sum of its proper divisors (43615005).

66400275 is a wasteful number, since it uses less digits than its factorization.

66400275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1895 (or 1890 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 66400275 is about 8148.6363889917. The cubic root of 66400275 is about 404.9393294272.

The spelling of 66400275 in words is "sixty-six million, four hundred thousand, two hundred seventy-five".