647135809 has 8 divisors (see below), whose sum is σ = 678768768. Its totient is φ = 616247280.

The previous prime is 647135807. The next prime is 647135857. The reversal of 647135809 is 908531746.

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 647135809 - 2¹ = 647135807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647135807) 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, 184327 + ... + 187804.

It is an arithmetic number, because the mean of its divisors is an integer number (84846096).

Almost surely, 2^647135809 is an apocalyptic number.

It is an amenable number.

647135809 is a deficient number, since it is larger than the sum of its proper divisors (31632959).

647135809 is a wasteful number, since it uses less digits than its factorization.

647135809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372215.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 647135809 is about 25438.8641452404. The cubic root of 647135809 is about 864.9648861418.

The spelling of 647135809 in words is "six hundred forty-seven million, one hundred thirty-five thousand, eight hundred nine".