64405609 has 2 divisors, whose sum is σ = 64405610. Its totient is φ = 64405608.

The previous prime is 64405603. The next prime is 64405613. The reversal of 64405609 is 90650446.

64405609 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., 58859584 + 5546025 = 7672^2 + 2355^2 .

It is a cyclic number.

It is not a de Polignac number, because 64405609 - 2¹¹ = 64403561 is a prime.

It is a super-3 number, since 3×64405609³ (a number of 24 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (64405603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32202804 + 32202805.

It is an arithmetic number, because the mean of its divisors is an integer number (32202805).

Almost surely, 2^64405609 is an apocalyptic number.

It is an amenable number.

64405609 is a deficient number, since it is larger than the sum of its proper divisors (1).

64405609 is an equidigital number, since it uses as much as digits as its factorization.

64405609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 64405609 is about 8025.3105235872. The cubic root of 64405609 is about 400.8432398672.

Subtracting from 64405609 its sum of digits (34), we obtain a triangular number (64405575 = T₁₁₃₄₉).

The spelling of 64405609 in words is "sixty-four million, four hundred five thousand, six hundred nine".