667909766 has 8 divisors (see below), whose sum is σ = 1014546720. Its totient is φ = 329727528.

The previous prime is 667909751. The next prime is 667909769.

It is a happy number.

667909766 is nontrivially palindromic in base 10.

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

It is a super-2 number, since 2×667909766² = 892206911036349512, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667909769) 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, 2113481 + ... + 2113796.

It is an arithmetic number, because the mean of its divisors is an integer number (126818340).

Almost surely, 2^667909766 is an apocalyptic number.

667909766 is a deficient number, since it is larger than the sum of its proper divisors (346636954).

667909766 is a wasteful number, since it uses less digits than its factorization.

667909766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4227358.

The product of its (nonzero) digits is 5143824, while the sum is 56.

The square root of 667909766 is about 25843.9502785468. The cubic root of 667909766 is about 874.1231012470.

The spelling of 667909766 in words is "six hundred sixty-seven million, nine hundred nine thousand, seven hundred sixty-six".