664322993 has 2 divisors, whose sum is σ = 664322994. Its totient is φ = 664322992.

The previous prime is 664322969. The next prime is 664322999. The reversal of 664322993 is 399223466.

664322993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 547185664 + 117137329 = 23392^2 + 10823^2 .

It is a cyclic number.

It is not a de Polignac number, because 664322993 - 2²⁶ = 597214129 is a prime.

It is not a weakly prime, because it can be changed into another prime (664322999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332161496 + 332161497.

It is an arithmetic number, because the mean of its divisors is an integer number (332161497).

Almost surely, 2^664322993 is an apocalyptic number.

It is an amenable number.

664322993 is a deficient number, since it is larger than the sum of its proper divisors (1).

664322993 is an equidigital number, since it uses as much as digits as its factorization.

664322993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 44.

The square root of 664322993 is about 25774.4639711479. The cubic root of 664322993 is about 872.5555690204. Note that the first 4 decimals are identical.

The spelling of 664322993 in words is "six hundred sixty-four million, three hundred twenty-two thousand, nine hundred ninety-three".