66385687 has 4 divisors (see below), whose sum is σ = 66994840. Its totient is φ = 65776536.

The previous prime is 66385681. The next prime is 66385717. The reversal of 66385687 is 78658366.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66385687 - 2⁷ = 66385559 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66385687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66385681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 304413 + ... + 304630.

It is an arithmetic number, because the mean of its divisors is an integer number (16748710).

Almost surely, 2^66385687 is an apocalyptic number.

66385687 is a deficient number, since it is larger than the sum of its proper divisors (609153).

66385687 is a wasteful number, since it uses less digits than its factorization.

66385687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609152.

The product of its digits is 1451520, while the sum is 49.

The square root of 66385687 is about 8147.7412207311. The cubic root of 66385687 is about 404.9096724838.

The spelling of 66385687 in words is "sixty-six million, three hundred eighty-five thousand, six hundred eighty-seven".