66445577 has 12 divisors (see below), whose sum is σ = 73771908. Its totient is φ = 59796000.

The previous prime is 66445573. The next prime is 66445579. The reversal of 66445577 is 77554466.

It can be written as a sum of positive squares in 2 ways, for example, as 53348416 + 13097161 = 7304^2 + 3619^2 .

It is not a de Polignac number, because 66445577 - 2² = 66445573 is a prime.

It is a Duffinian number.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66445573) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9503 + ... + 14939.

It is an arithmetic number, because the mean of its divisors is an integer number (6147659).

Almost surely, 2^66445577 is an apocalyptic number.

It is an amenable number.

66445577 is a deficient number, since it is larger than the sum of its proper divisors (7326331).

66445577 is a wasteful number, since it uses less digits than its factorization.

66445577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5560 (or 5549 counting only the distinct ones).

The product of its digits is 705600, while the sum is 44.

The square root of 66445577 is about 8151.4156439235. The cubic root of 66445577 is about 405.0313992828.

Subtracting 66445577 from its reverse (77554466), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 6644 and 5577, that added together give a palindrome (12221).

The spelling of 66445577 in words is "sixty-six million, four hundred forty-five thousand, five hundred seventy-seven".