64478009 has 2 divisors, whose sum is σ = 64478010. Its totient is φ = 64478008.

The previous prime is 64477999. The next prime is 64478023. The reversal of 64478009 is 90087446.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64320400 + 157609 = 8020^2 + 397^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64478009 is a prime.

It is not a weakly prime, because it can be changed into another prime (64478509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32239004 + 32239005.

It is an arithmetic number, because the mean of its divisors is an integer number (32239005).

Almost surely, 2^64478009 is an apocalyptic number.

It is an amenable number.

64478009 is a deficient number, since it is larger than the sum of its proper divisors (1).

64478009 is an equidigital number, since it uses as much as digits as its factorization.

64478009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 64478009 is about 8029.8199855289. The cubic root of 64478009 is about 400.9933830165.

The spelling of 64478009 in words is "sixty-four million, four hundred seventy-eight thousand, nine".