64695207809 has 4 divisors (see below), whose sum is σ = 64756764720. Its totient is φ = 64633650900.

The previous prime is 64695207781. The next prime is 64695207817. The reversal of 64695207809 is 90870259646.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64695207809 - 2¹⁶ = 64695142273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64695207209) 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, 30776879 + ... + 30778980.

It is an arithmetic number, because the mean of its divisors is an integer number (16189191180).

Almost surely, 2^64695207809 is an apocalyptic number.

It is an amenable number.

64695207809 is a deficient number, since it is larger than the sum of its proper divisors (61556911).

64695207809 is a wasteful number, since it uses less digits than its factorization.

64695207809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61556910.

The product of its (nonzero) digits is 6531840, while the sum is 56.

The spelling of 64695207809 in words is "sixty-four billion, six hundred ninety-five million, two hundred seven thousand, eight hundred nine".