664275761 has 2 divisors, whose sum is σ = 664275762. Its totient is φ = 664275760.

The previous prime is 664275751. The next prime is 664275779. The reversal of 664275761 is 167572466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 637815025 + 26460736 = 25255^2 + 5144^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664275761 is a prime.

It is not a weakly prime, because it can be changed into another prime (664275751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332137880 + 332137881.

It is an arithmetic number, because the mean of its divisors is an integer number (332137881).

Almost surely, 2^664275761 is an apocalyptic number.

It is an amenable number.

664275761 is a deficient number, since it is larger than the sum of its proper divisors (1).

664275761 is an equidigital number, since it uses as much as digits as its factorization.

664275761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 44.

The square root of 664275761 is about 25773.5476991430. The cubic root of 664275761 is about 872.5348895608.

The spelling of 664275761 in words is "six hundred sixty-four million, two hundred seventy-five thousand, seven hundred sixty-one".