664028138 has 16 divisors (see below), whose sum is σ = 1031006880. Its totient is φ = 320372976.

The previous prime is 664028129. The next prime is 664028161. The reversal of 664028138 is 831820466.

It is a happy number.

664028138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162881 + ... + 166907.

It is an arithmetic number, because the mean of its divisors is an integer number (64437930).

Almost surely, 2^664028138 is an apocalyptic number.

664028138 is a deficient number, since it is larger than the sum of its proper divisors (366978742).

664028138 is a wasteful number, since it uses less digits than its factorization.

664028138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6901.

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 664028138 is about 25768.7434307535. The cubic root of 664028138 is about 872.4264574045.

It can be divided in two parts, 66 and 4028138, that added together give a palindrome (4028204).

The spelling of 664028138 in words is "six hundred sixty-four million, twenty-eight thousand, one hundred thirty-eight".