66504609 has 6 divisors (see below), whose sum is σ = 96062226. Its totient is φ = 44336400.

The previous prime is 66504587. The next prime is 66504631. The reversal of 66504609 is 90640566.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66504587) and next prime (66504631).

It can be written as a sum of positive squares in only one way, i.e., 50126400 + 16378209 = 7080^2 + 4047^2 .

It is not a de Polignac number, because 66504609 - 2⁸ = 66504353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66574609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3694692 + ... + 3694709.

It is an arithmetic number, because the mean of its divisors is an integer number (16010371).

Almost surely, 2^66504609 is an apocalyptic number.

It is an amenable number.

66504609 is a deficient number, since it is larger than the sum of its proper divisors (29557617).

66504609 is a wasteful number, since it uses less digits than its factorization.

66504609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7389407 (or 7389404 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 66504609 is about 8155.0358061752. The cubic root of 66504609 is about 405.1513106320.

The spelling of 66504609 in words is "sixty-six million, five hundred four thousand, six hundred nine".