66386387 has 4 divisors (see below), whose sum is σ = 67511640. Its totient is φ = 65261136.

The previous prime is 66386381. The next prime is 66386401. The reversal of 66386387 is 78368366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78368366 = 2 ⋅39184183.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66386387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66386381) 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, 562538 + ... + 562655.

It is an arithmetic number, because the mean of its divisors is an integer number (16877910).

Almost surely, 2^66386387 is an apocalyptic number.

66386387 is a deficient number, since it is larger than the sum of its proper divisors (1125253).

66386387 is a wasteful number, since it uses less digits than its factorization.

66386387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1125252.

The product of its digits is 870912, while the sum is 47.

The square root of 66386387 is about 8147.7841773086. The cubic root of 66386387 is about 404.9110956610.

The spelling of 66386387 in words is "sixty-six million, three hundred eighty-six thousand, three hundred eighty-seven".