664846646 has 16 divisors (see below), whose sum is σ = 1030070400. Its totient is φ = 321503040.

The previous prime is 664846639. The next prime is 664846657. The reversal of 664846646 is 646648466.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 664846594 and 664846603.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 187280 + ... + 190796.

It is an arithmetic number, because the mean of its divisors is an integer number (64379400).

Almost surely, 2^664846646 is an apocalyptic number.

664846646 is a deficient number, since it is larger than the sum of its proper divisors (365223754).

664846646 is a wasteful number, since it uses less digits than its factorization.

664846646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6599.

The product of its digits is 3981312, while the sum is 50.

The square root of 664846646 is about 25784.6203384886. The cubic root of 664846646 is about 872.7847729588.

The spelling of 664846646 in words is "six hundred sixty-four million, eight hundred forty-six thousand, six hundred forty-six".