664318643 has 2 divisors, whose sum is σ = 664318644. Its totient is φ = 664318642.

The previous prime is 664318621. The next prime is 664318651. The reversal of 664318643 is 346813466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664318643 - 2¹⁴ = 664302259 is a prime.

It is a super-2 number, since 2×664318643² = 882638518874722898, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 664318643.

It is not a weakly prime, because it can be changed into another prime (664318943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332159321 + 332159322.

It is an arithmetic number, because the mean of its divisors is an integer number (332159322).

Almost surely, 2^664318643 is an apocalyptic number.

664318643 is a deficient number, since it is larger than the sum of its proper divisors (1).

664318643 is an equidigital number, since it uses as much as digits as its factorization.

664318643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 41.

The square root of 664318643 is about 25774.3795851617. The cubic root of 664318643 is about 872.5536645126.

The spelling of 664318643 in words is "six hundred sixty-four million, three hundred eighteen thousand, six hundred forty-three".