651680305 has 4 divisors (see below), whose sum is σ = 782016372. Its totient is φ = 521344240.

The previous prime is 651680303. The next prime is 651680317. The reversal of 651680305 is 503086156.

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 235561104 + 416119201 = 15348^2 + 20399^2 .

It is not a de Polignac number, because 651680305 - 2¹ = 651680303 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (651680303) 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, 65168026 + ... + 65168035.

It is an arithmetic number, because the mean of its divisors is an integer number (195504093).

Almost surely, 2^651680305 is an apocalyptic number.

It is an amenable number.

651680305 is a deficient number, since it is larger than the sum of its proper divisors (130336067).

651680305 is a wasteful number, since it uses less digits than its factorization.

651680305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130336066.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 651680305 is about 25528.0297908005. The cubic root of 651680305 is about 866.9848968597.

The spelling of 651680305 in words is "six hundred fifty-one million, six hundred eighty thousand, three hundred five".