666943984 has 40 divisors (see below), whose sum is σ = 1479016448. Its totient is φ = 285405120.

The previous prime is 666943969. The next prime is 666943993. The reversal of 666943984 is 489349666.

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 77329 + ... + 85519.

Almost surely, 2^666943984 is an apocalyptic number.

It is an amenable number.

666943984 is an abundant number, since it is smaller than the sum of its proper divisors (812072464).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666943984 is a wasteful number, since it uses less digits than its factorization.

666943984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8933 (or 8927 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 55.

The square root of 666943984 is about 25825.2586434289. The cubic root of 666943984 is about 873.7015774470.

It can be divided in two parts, 6669 and 43984, that added together give a cube (50653 = 37³).

The spelling of 666943984 in words is "six hundred sixty-six million, nine hundred forty-three thousand, nine hundred eighty-four".