667996399 has 8 divisors (see below), whose sum is σ = 770560128. Its totient is φ = 567216600.

The previous prime is 667996393. The next prime is 667996447. The reversal of 667996399 is 993699766.

It is a happy number.

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 667996399 - 2³ = 667996391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 667996399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667996391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 445177 + ... + 446674.

It is an arithmetic number, because the mean of its divisors is an integer number (96320016).

Almost surely, 2^667996399 is an apocalyptic number.

667996399 is a deficient number, since it is larger than the sum of its proper divisors (102563729).

667996399 is a wasteful number, since it uses less digits than its factorization.

667996399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891965.

The product of its digits is 29760696, while the sum is 64.

The square root of 667996399 is about 25845.6263031098. The cubic root of 667996399 is about 874.1608930949.

The spelling of 667996399 in words is "six hundred sixty-seven million, nine hundred ninety-six thousand, three hundred ninety-nine".