1664340961 has 2 divisors, whose sum is σ = 1664340962. Its totient is φ = 1664340960.

The previous prime is 1664340941. The next prime is 1664341009. The reversal of 1664340961 is 1690434661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1015059600 + 649281361 = 31860^2 + 25481^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664340961 - 2¹⁷ = 1664209889 is a prime.

It is not a weakly prime, because it can be changed into another prime (1664340901) 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, 832170480 + 832170481.

It is an arithmetic number, because the mean of its divisors is an integer number (832170481).

Almost surely, 2^1664340961 is an apocalyptic number.

It is an amenable number.

1664340961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664340961 is an equidigital number, since it uses as much as digits as its factorization.

1664340961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 1664340961 is about 40796.3351417747. The cubic root of 1664340961 is about 1185.0793589846.

The spelling of 1664340961 in words is "one billion, six hundred sixty-four million, three hundred forty thousand, nine hundred sixty-one".