666784367 has 4 divisors (see below), whose sum is σ = 671874456. Its totient is φ = 661694280.

The previous prime is 666784337. The next prime is 666784379. The reversal of 666784367 is 763487666.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666784367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666784337) 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 3 ways as a sum of consecutive naturals, for example, 2544848 + ... + 2545109.

It is an arithmetic number, because the mean of its divisors is an integer number (167968614).

Almost surely, 2^666784367 is an apocalyptic number.

666784367 is a deficient number, since it is larger than the sum of its proper divisors (5090089).

666784367 is a wasteful number, since it uses less digits than its factorization.

666784367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5090088.

The product of its digits is 6096384, while the sum is 53.

The square root of 666784367 is about 25822.1681312782. The cubic root of 666784367 is about 873.6318720670.

The spelling of 666784367 in words is "six hundred sixty-six million, seven hundred eighty-four thousand, three hundred sixty-seven".