664355749 has 2 divisors, whose sum is σ = 664355750. Its totient is φ = 664355748.

The previous prime is 664355743. The next prime is 664355789. The reversal of 664355749 is 947553466.

It is a happy number.

664355749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 414936900 + 249418849 = 20370^2 + 15793^2 .

It is a cyclic number.

It is not a de Polignac number, because 664355749 - 2⁵ = 664355717 is a prime.

It is a super-2 number, since 2×664355749² = 882737122458702002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664355743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332177874 + 332177875.

It is an arithmetic number, because the mean of its divisors is an integer number (332177875).

Almost surely, 2^664355749 is an apocalyptic number.

It is an amenable number.

664355749 is a deficient number, since it is larger than the sum of its proper divisors (1).

664355749 is an equidigital number, since it uses as much as digits as its factorization.

664355749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2721600, while the sum is 49.

The square root of 664355749 is about 25775.0993984504. The cubic root of 664355749 is about 872.5699099162.

The spelling of 664355749 in words is "six hundred sixty-four million, three hundred fifty-five thousand, seven hundred forty-nine".