664804138 has 8 divisors (see below), whose sum is σ = 1010866788. Its totient is φ = 327848544.

The previous prime is 664804117. The next prime is 664804157. The reversal of 664804138 is 831408466.

It can be written as a sum of positive squares in 2 ways, for example, as 662908009 + 1896129 = 25747^2 + 1377^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 664804138.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2276581 + ... + 2276872.

Almost surely, 2^664804138 is an apocalyptic number.

664804138 is a deficient number, since it is larger than the sum of its proper divisors (346062650).

664804138 is a wasteful number, since it uses less digits than its factorization.

664804138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4553528.

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 664804138 is about 25783.7960354949. The cubic root of 664804138 is about 872.7661716136.

The spelling of 664804138 in words is "six hundred sixty-four million, eight hundred four thousand, one hundred thirty-eight".