664838672389 has 2 divisors, whose sum is σ = 664838672390. Its totient is φ = 664838672388.

The previous prime is 664838672341. The next prime is 664838672423. The reversal of 664838672389 is 983276838466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 625973704225 + 38864968164 = 791185^2 + 197142^2 .

It is a cyclic number.

It is not a de Polignac number, because 664838672389 - 2²¹ = 664836575237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664838672789) 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, 332419336194 + 332419336195.

It is an arithmetic number, because the mean of its divisors is an integer number (332419336195).

Almost surely, 2^664838672389 is an apocalyptic number.

It is an amenable number.

664838672389 is a deficient number, since it is larger than the sum of its proper divisors (1).

664838672389 is an equidigital number, since it uses as much as digits as its factorization.

664838672389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 501645312, while the sum is 70.

The spelling of 664838672389 in words is "six hundred sixty-four billion, eight hundred thirty-eight million, six hundred seventy-two thousand, three hundred eighty-nine".