666288386 has 4 divisors (see below), whose sum is σ = 999432582. Its totient is φ = 333144192.

The previous prime is 666288379. The next prime is 666288407. The reversal of 666288386 is 683882666.

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

It can be written as a sum of positive squares in only one way, i.e., 634082761 + 32205625 = 25181^2 + 5675^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166572095 + ... + 166572098.

Almost surely, 2^666288386 is an apocalyptic number.

666288386 is a deficient number, since it is larger than the sum of its proper divisors (333144196).

666288386 is a wasteful number, since it uses less digits than its factorization.

666288386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333144195.

The product of its digits is 3981312, while the sum is 53.

The square root of 666288386 is about 25812.5625616675. The cubic root of 666288386 is about 873.4152041746.

The spelling of 666288386 in words is "six hundred sixty-six million, two hundred eighty-eight thousand, three hundred eighty-six".