664651061 has 2 divisors, whose sum is σ = 664651062. Its totient is φ = 664651060.

The previous prime is 664651051. The next prime is 664651073. The reversal of 664651061 is 160156466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 440580100 + 224070961 = 20990^2 + 14969^2 .

It is a cyclic number.

It is not a de Polignac number, because 664651061 - 2⁶ = 664650997 is a prime.

It is a super-2 number, since 2×664651061² = 883522065776851442, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664651051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332325530 + 332325531.

It is an arithmetic number, because the mean of its divisors is an integer number (332325531).

Almost surely, 2^664651061 is an apocalyptic number.

It is an amenable number.

664651061 is a deficient number, since it is larger than the sum of its proper divisors (1).

664651061 is an equidigital number, since it uses as much as digits as its factorization.

664651061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 664651061 is about 25780.8273916878. The cubic root of 664651061 is about 872.6991791090.

The spelling of 664651061 in words is "six hundred sixty-four million, six hundred fifty-one thousand, sixty-one".