665167809 has 8 divisors (see below), whose sum is σ = 917472960. Its totient is φ = 428153936.

The previous prime is 665167807. The next prime is 665167819. The reversal of 665167809 is 908761566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665167809 - 2¹ = 665167807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665167801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3822717 + ... + 3822890.

It is an arithmetic number, because the mean of its divisors is an integer number (114684120).

Almost surely, 2^665167809 is an apocalyptic number.

It is an amenable number.

665167809 is a deficient number, since it is larger than the sum of its proper divisors (252305151).

665167809 is a wasteful number, since it uses less digits than its factorization.

665167809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7645639.

The product of its (nonzero) digits is 544320, while the sum is 48.

The square root of 665167809 is about 25790.8473881724. The cubic root of 665167809 is about 872.9252870932.

The spelling of 665167809 in words is "six hundred sixty-five million, one hundred sixty-seven thousand, eight hundred nine".