664355789 has 2 divisors, whose sum is σ = 664355790. Its totient is φ = 664355788.

The previous prime is 664355749. The next prime is 664355803. The reversal of 664355789 is 987553466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 379860100 + 284495689 = 19490^2 + 16867^2 .

It is a cyclic number.

It is not a de Polignac number, because 664355789 - 2¹² = 664351693 is a prime.

It is a super-2 number, since 2×664355789² = 882737228755625042, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 664355789.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664355749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332177894 + 332177895.

It is an arithmetic number, because the mean of its divisors is an integer number (332177895).

Almost surely, 2^664355789 is an apocalyptic number.

It is an amenable number.

664355789 is a deficient number, since it is larger than the sum of its proper divisors (1).

664355789 is an equidigital number, since it uses as much as digits as its factorization.

664355789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5443200, while the sum is 53.

The square root of 664355789 is about 25775.1001743931. The cubic root of 664355789 is about 872.5699274283.

The spelling of 664355789 in words is "six hundred sixty-four million, three hundred fifty-five thousand, seven hundred eighty-nine".