66575661 has 4 divisors (see below), whose sum is σ = 88767552. Its totient is φ = 44383772.

The previous prime is 66575657. The next prime is 66575669. The reversal of 66575661 is 16657566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66575661 - 2² = 66575657 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66575669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11095941 + ... + 11095946.

It is an arithmetic number, because the mean of its divisors is an integer number (22191888).

Almost surely, 2^66575661 is an apocalyptic number.

It is an amenable number.

66575661 is a deficient number, since it is larger than the sum of its proper divisors (22191891).

66575661 is a wasteful number, since it uses less digits than its factorization.

66575661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22191890.

The product of its digits is 226800, while the sum is 42.

The square root of 66575661 is about 8159.3909699193. The cubic root of 66575661 is about 405.2955440704.

The spelling of 66575661 in words is "sixty-six million, five hundred seventy-five thousand, six hundred sixty-one".