648409717 has 4 divisors (see below), whose sum is σ = 654358540. Its totient is φ = 642460896.

The previous prime is 648409703. The next prime is 648409747. The reversal of 648409717 is 717904846.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 717904846 = 2 ⋅358952423.

It can be written as a sum of positive squares in 2 ways, for example, as 244640881 + 403768836 = 15641^2 + 20094^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-648409717 is a prime.

It is a super-2 number, since 2×648409717² = 840870322200040178, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648409747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2974248 + ... + 2974465.

It is an arithmetic number, because the mean of its divisors is an integer number (163589635).

Almost surely, 2^648409717 is an apocalyptic number.

It is an amenable number.

648409717 is a deficient number, since it is larger than the sum of its proper divisors (5948823).

648409717 is a wasteful number, since it uses less digits than its factorization.

648409717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5948822.

The product of its (nonzero) digits is 338688, while the sum is 46.

The square root of 648409717 is about 25463.8904529532. The cubic root of 648409717 is about 865.5320846752.

The spelling of 648409717 in words is "six hundred forty-eight million, four hundred nine thousand, seven hundred seventeen".