648927217 has 4 divisors (see below), whose sum is σ = 649347700. Its totient is φ = 648506736.

The previous prime is 648927161. The next prime is 648927269. The reversal of 648927217 is 712729846.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 498227041 + 150700176 = 22321^2 + 12276^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-648927217 is a prime.

It is a super-2 number, since 2×648927217² = 842213065926730178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (648967217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207918 + ... + 211015.

It is an arithmetic number, because the mean of its divisors is an integer number (162336925).

Almost surely, 2^648927217 is an apocalyptic number.

It is an amenable number.

648927217 is a deficient number, since it is larger than the sum of its proper divisors (420483).

648927217 is a wasteful number, since it uses less digits than its factorization.

648927217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420482.

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

The square root of 648927217 is about 25474.0498743329. The cubic root of 648927217 is about 865.7622857009.

The spelling of 648927217 in words is "six hundred forty-eight million, nine hundred twenty-seven thousand, two hundred seventeen".