64405309 has 2 divisors, whose sum is σ = 64405310. Its totient is φ = 64405308.

The previous prime is 64405283. The next prime is 64405331. The reversal of 64405309 is 90350446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43520409 + 20884900 = 6597^2 + 4570^2 .

It is a cyclic number.

It is not a de Polignac number, because 64405309 - 2²⁵ = 30850877 is a prime.

It is a super-3 number, since 3×64405309³ (a number of 24 digits) contains 333 as substring.

It is a Chen prime.

It is equal to p_3807652 and since 64405309 and 3807652 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64405349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32202654 + 32202655.

It is an arithmetic number, because the mean of its divisors is an integer number (32202655).

Almost surely, 2^64405309 is an apocalyptic number.

It is an amenable number.

64405309 is a deficient number, since it is larger than the sum of its proper divisors (1).

64405309 is an equidigital number, since it uses as much as digits as its factorization.

64405309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 64405309 is about 8025.2918326999. The cubic root of 64405309 is about 400.8426174930.

The spelling of 64405309 in words is "sixty-four million, four hundred five thousand, three hundred nine".