664378 has 32 divisors (see below), whose sum is σ = 1233792. Its totient is φ = 264000.

The previous prime is 664369. The next prime is 664379. The reversal of 664378 is 873466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664379) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6528 + ... + 6628.

It is an arithmetic number, because the mean of its divisors is an integer number (38556).

2⁶⁶⁴³⁷⁸ is an apocalyptic number.

664378 is a deficient number, since it is larger than the sum of its proper divisors (569414).

664378 is a wasteful number, since it uses less digits than its factorization.

664378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150.

The product of its digits is 24192, while the sum is 34.

The square root of 664378 is about 815.0938596260. The cubic root of 664378 is about 87.2579651352.

It can be divided in two parts, 66 and 4378, that added together give a palindrome (4444).

The spelling of 664378 in words is "six hundred sixty-four thousand, three hundred seventy-eight".