1666670387 has 8 divisors (see below), whose sum is σ = 1684184832. Its totient is φ = 1649176000.

The previous prime is 1666670381. The next prime is 1666670407. The reversal of 1666670387 is 7830766661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666670387 - 2⁶ = 1666670323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666670381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 209303 + ... + 217119.

It is an arithmetic number, because the mean of its divisors is an integer number (210523104).

Almost surely, 2^1666670387 is an apocalyptic number.

1666670387 is a deficient number, since it is larger than the sum of its proper divisors (17514445).

1666670387 is a wasteful number, since it uses less digits than its factorization.

1666670387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10029.

The product of its (nonzero) digits is 1524096, while the sum is 50.

The square root of 1666670387 is about 40824.8746109526. The cubic root of 1666670387 is about 1185.6319836846.

The spelling of 1666670387 in words is "one billion, six hundred sixty-six million, six hundred seventy thousand, three hundred eighty-seven".