664724393 has 2 divisors, whose sum is σ = 664724394. Its totient is φ = 664724392.

The previous prime is 664724371. The next prime is 664724441. The reversal of 664724393 is 393427466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 474063529 + 190660864 = 21773^2 + 13808^2 .

It is a cyclic number.

It is not a de Polignac number, because 664724393 - 2¹⁶ = 664658857 is a prime.

It is not a weakly prime, because it can be changed into another prime (664724363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332362196 + 332362197.

It is an arithmetic number, because the mean of its divisors is an integer number (332362197).

Almost surely, 2^664724393 is an apocalyptic number.

It is an amenable number.

664724393 is a deficient number, since it is larger than the sum of its proper divisors (1).

664724393 is an equidigital number, since it uses as much as digits as its factorization.

664724393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 44.

The square root of 664724393 is about 25782.2495721378. The cubic root of 664724393 is about 872.7312733544.

The spelling of 664724393 in words is "six hundred sixty-four million, seven hundred twenty-four thousand, three hundred ninety-three".