64509817 has 8 divisors (see below), whose sum is σ = 65104776. Its totient is φ = 63917952.

The previous prime is 64509799. The next prime is 64509821. The reversal of 64509817 is 71890546.

It can be written as a sum of positive squares in 4 ways, for example, as 29333056 + 35176761 = 5416^2 + 5931^2 .

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 64509817 - 2⁷ = 64509689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64509817.

It is not an unprimeable number, because it can be changed into a prime (64509877) 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, 61933 + ... + 62965.

It is an arithmetic number, because the mean of its divisors is an integer number (8138097).

Almost surely, 2^64509817 is an apocalyptic number.

It is an amenable number.

64509817 is a deficient number, since it is larger than the sum of its proper divisors (594959).

64509817 is a wasteful number, since it uses less digits than its factorization.

64509817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1547.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 64509817 is about 8031.8003585747. The cubic root of 64509817 is about 401.0593109245.

The spelling of 64509817 in words is "sixty-four million, five hundred nine thousand, eight hundred seventeen".