664120826 has 4 divisors (see below), whose sum is σ = 996181242. Its totient is φ = 332060412.

The previous prime is 664120777. The next prime is 664120867. The reversal of 664120826 is 628021466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 460059601 + 204061225 = 21449^2 + 14285^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166030205 + ... + 166030208.

Almost surely, 2^664120826 is an apocalyptic number.

664120826 is a deficient number, since it is larger than the sum of its proper divisors (332060416).

664120826 is a wasteful number, since it uses less digits than its factorization.

664120826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332060415.

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 664120826 is about 25770.5418258910. The cubic root of 664120826 is about 872.4670479040.

The spelling of 664120826 in words is "six hundred sixty-four million, one hundred twenty thousand, eight hundred twenty-six".