65438809 has 4 divisors (see below), whose sum is σ = 66086820. Its totient is φ = 64790800.

The previous prime is 65438803. The next prime is 65438827. The reversal of 65438809 is 90883456.

65438809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58859584 + 6579225 = 7672^2 + 2565^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65438809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65438803) 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 in 3 ways as a sum of consecutive naturals, for example, 323854 + ... + 324055.

It is an arithmetic number, because the mean of its divisors is an integer number (16521705).

Almost surely, 2^65438809 is an apocalyptic number.

It is an amenable number.

65438809 is a deficient number, since it is larger than the sum of its proper divisors (648011).

65438809 is a wasteful number, since it uses less digits than its factorization.

65438809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648010.

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 65438809 is about 8089.4257521780. The cubic root of 65438809 is about 402.9753323694.

The spelling of 65438809 in words is "sixty-five million, four hundred thirty-eight thousand, eight hundred nine".