66400075 has 36 divisors (see below), whose sum is σ = 96598480. Its totient is φ = 44349120.

The previous prime is 66400073. The next prime is 66400091. The reversal of 66400075 is 57000466.

It is not a de Polignac number, because 66400075 - 2¹ = 66400073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66400073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 609121 + ... + 609229.

Almost surely, 2^66400075 is an apocalyptic number.

66400075 is a deficient number, since it is larger than the sum of its proper divisors (30198405).

66400075 is a wasteful number, since it uses less digits than its factorization.

66400075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 66400075 is about 8148.6241169905. The cubic root of 66400075 is about 404.9389228629.

The spelling of 66400075 in words is "sixty-six million, four hundred thousand, seventy-five".