664051697 has 2 divisors, whose sum is σ = 664051698. Its totient is φ = 664051696.

The previous prime is 664051679. The next prime is 664051721. The reversal of 664051697 is 796150466.

It is a happy number.

Together with previous prime (664051679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 647397136 + 16654561 = 25444^2 + 4081^2 .

It is a cyclic number.

It is not a de Polignac number, because 664051697 - 2⁸ = 664051441 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (664051627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332025848 + 332025849.

It is an arithmetic number, because the mean of its divisors is an integer number (332025849).

Almost surely, 2^664051697 is an apocalyptic number.

It is an amenable number.

664051697 is a deficient number, since it is larger than the sum of its proper divisors (1).

664051697 is an equidigital number, since it uses as much as digits as its factorization.

664051697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 664051697 is about 25769.2005502693. The cubic root of 664051697 is about 872.4367748648.

The spelling of 664051697 in words is "six hundred sixty-four million, fifty-one thousand, six hundred ninety-seven".