66666575 has 6 divisors (see below), whose sum is σ = 82666584. Its totient is φ = 53333240.

The previous prime is 66666569. The next prime is 66666629. The reversal of 66666575 is 57566666.

It is not a de Polignac number, because 66666575 - 2⁴ = 66666559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1333307 + ... + 1333356.

It is an arithmetic number, because the mean of its divisors is an integer number (13777764).

Almost surely, 2^66666575 is an apocalyptic number.

66666575 is a deficient number, since it is larger than the sum of its proper divisors (16000009).

66666575 is a wasteful number, since it uses less digits than its factorization.

66666575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2666673 (or 2666668 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 47.

The square root of 66666575 is about 8164.9601958613. The cubic root of 66666575 is about 405.4799471931.

Subtracting from 66666575 its reverse (57566666), we obtain a palindrome (9099909).

The spelling of 66666575 in words is "sixty-six million, six hundred sixty-six thousand, five hundred seventy-five".