664641322 has 4 divisors (see below), whose sum is σ = 996961986. Its totient is φ = 332320660.

The previous prime is 664641319. The next prime is 664641347. The reversal of 664641322 is 223146466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 223146466 = 2 ⋅111573233.

It can be written as a sum of positive squares in only one way, i.e., 610633521 + 54007801 = 24711^2 + 7349^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166160329 + ... + 166160332.

Almost surely, 2^664641322 is an apocalyptic number.

664641322 is a deficient number, since it is larger than the sum of its proper divisors (332320664).

664641322 is a wasteful number, since it uses less digits than its factorization.

664641322 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332320663.

The product of its digits is 41472, while the sum is 34.

The square root of 664641322 is about 25780.6385103240. The cubic root of 664641322 is about 872.6949165923.

Adding to 664641322 its reverse (223146466), we get a palindrome (887787788).

The spelling of 664641322 in words is "six hundred sixty-four million, six hundred forty-one thousand, three hundred twenty-two".