64716443509 has 2 divisors, whose sum is σ = 64716443510. Its totient is φ = 64716443508.

The previous prime is 64716443497. The next prime is 64716443527. The reversal of 64716443509 is 90534461746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64568334609 + 148108900 = 254103^2 + 12170^2 .

It is a cyclic number.

It is not a de Polignac number, because 64716443509 - 2⁹ = 64716442997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64716443009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32358221754 + 32358221755.

It is an arithmetic number, because the mean of its divisors is an integer number (32358221755).

Almost surely, 2^64716443509 is an apocalyptic number.

It is an amenable number.

64716443509 is a deficient number, since it is larger than the sum of its proper divisors (1).

64716443509 is an equidigital number, since it uses as much as digits as its factorization.

64716443509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 49.

The spelling of 64716443509 in words is "sixty-four billion, seven hundred sixteen million, four hundred forty-three thousand, five hundred nine".