66641577 has 4 divisors (see below), whose sum is σ = 88855440. Its totient is φ = 44427716.

The previous prime is 66641573. The next prime is 66641579. The reversal of 66641577 is 77514666.

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 66641577 - 2² = 66641573 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66641573) 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 3 ways as a sum of consecutive naturals, for example, 11106927 + ... + 11106932.

It is an arithmetic number, because the mean of its divisors is an integer number (22213860).

Almost surely, 2^66641577 is an apocalyptic number.

It is an amenable number.

66641577 is a deficient number, since it is larger than the sum of its proper divisors (22213863).

66641577 is a wasteful number, since it uses less digits than its factorization.

66641577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22213862.

The product of its digits is 211680, while the sum is 42.

The square root of 66641577 is about 8163.4292426651. The cubic root of 66641577 is about 405.4292598488.

The spelling of 66641577 in words is "sixty-six million, six hundred forty-one thousand, five hundred seventy-seven".