66557575 has 12 divisors (see below), whose sum is σ = 94321840. Its totient is φ = 45639360.

The previous prime is 66557549. The next prime is 66557597. The reversal of 66557575 is 57575566.

It is not a de Polignac number, because 66557575 - 2¹⁵ = 66524807 is a prime.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 189990 + ... + 190339.

Almost surely, 2^66557575 is an apocalyptic number.

66557575 is a deficient number, since it is larger than the sum of its proper divisors (27764265).

66557575 is a wasteful number, since it uses less digits than its factorization.

66557575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380346 (or 380341 counting only the distinct ones).

The product of its digits is 1102500, while the sum is 46.

The square root of 66557575 is about 8158.2826011361. The cubic root of 66557575 is about 405.2588397705.

Subtracting from 66557575 its reverse (57575566), we obtain a square (8982009 = 2997²).

The spelling of 66557575 in words is "sixty-six million, five hundred fifty-seven thousand, five hundred seventy-five".