664574789 has 2 divisors, whose sum is σ = 664574790. Its totient is φ = 664574788.

The previous prime is 664574777. The next prime is 664574803. The reversal of 664574789 is 987475466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 502521889 + 162052900 = 22417^2 + 12730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664574789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664574749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332287394 + 332287395.

It is an arithmetic number, because the mean of its divisors is an integer number (332287395).

Almost surely, 2^664574789 is an apocalyptic number.

It is an amenable number.

664574789 is a deficient number, since it is larger than the sum of its proper divisors (1).

664574789 is an equidigital number, since it uses as much as digits as its factorization.

664574789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10160640, while the sum is 56.

The square root of 664574789 is about 25779.3481104546. The cubic root of 664574789 is about 872.6657956481.

The spelling of 664574789 in words is "six hundred sixty-four million, five hundred seventy-four thousand, seven hundred eighty-nine".