664878398 has 8 divisors (see below), whose sum is σ = 1055983392. Its totient is φ = 312883936.

The previous prime is 664878397. The next prime is 664878407. The reversal of 664878398 is 893878466.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664878397) 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, 9777590 + ... + 9777657.

It is an arithmetic number, because the mean of its divisors is an integer number (131997924).

Almost surely, 2^664878398 is an apocalyptic number.

664878398 is a deficient number, since it is larger than the sum of its proper divisors (391104994).

664878398 is a wasteful number, since it uses less digits than its factorization.

664878398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19555266.

The product of its digits is 13934592, while the sum is 59.

The square root of 664878398 is about 25785.2360470095. The cubic root of 664878398 is about 872.7986670004.

The spelling of 664878398 in words is "six hundred sixty-four million, eight hundred seventy-eight thousand, three hundred ninety-eight".