1666667387 has 16 divisors (see below), whose sum is σ = 2088384000. Its totient is φ = 1292163840.

The previous prime is 1666667383. The next prime is 1666667393. The reversal of 1666667387 is 7837666661.

It is not a de Polignac number, because 1666667387 - 2² = 1666667383 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666667383) 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 15 ways as a sum of consecutive naturals, for example, 39062 + ... + 69707.

It is an arithmetic number, because the mean of its divisors is an integer number (130524000).

Almost surely, 2^1666667387 is an apocalyptic number.

1666667387 is a deficient number, since it is larger than the sum of its proper divisors (421716613).

1666667387 is a wasteful number, since it uses less digits than its factorization.

1666667387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108986.

The product of its digits is 9144576, while the sum is 56.

The square root of 1666667387 is about 40824.8378686309. The cubic root of 1666667387 is about 1185.6312723066.

The spelling of 1666667387 in words is "one billion, six hundred sixty-six million, six hundred sixty-seven thousand, three hundred eighty-seven".