667378331 has 4 divisors (see below), whose sum is σ = 667452600. Its totient is φ = 667304064.

The previous prime is 667378319. The next prime is 667378343. The reversal of 667378331 is 133873766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (667378319) and next prime (667378343).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667378331 is a prime.

It is a super-2 number, since 2×667378331² = 890787673376691122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667378351) 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 3 ways as a sum of consecutive naturals, for example, 21446 + ... + 42363.

It is an arithmetic number, because the mean of its divisors is an integer number (166863150).

Almost surely, 2^667378331 is an apocalyptic number.

667378331 is a deficient number, since it is larger than the sum of its proper divisors (74269).

667378331 is a wasteful number, since it uses less digits than its factorization.

667378331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74268.

The product of its digits is 381024, while the sum is 44.

The square root of 667378331 is about 25833.6666193554. Note that the first 4 decimals coincide. The cubic root of 667378331 is about 873.8912022216.

The spelling of 667378331 in words is "six hundred sixty-seven million, three hundred seventy-eight thousand, three hundred thirty-one".