649128580 has 24 divisors (see below), whose sum is σ = 1373581440. Its totient is φ = 257668320.

The previous prime is 649128553. The next prime is 649128581. The reversal of 649128580 is 85821946.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (649128581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121260 + ... + 126499.

It is an arithmetic number, because the mean of its divisors is an integer number (57232560).

Almost surely, 2^649128580 is an apocalyptic number.

It is an amenable number.

649128580 is an abundant number, since it is smaller than the sum of its proper divisors (724452860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649128580 is a wasteful number, since it uses less digits than its factorization.

649128580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247899 (or 247897 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 649128580 is about 25478.0018839783. The cubic root of 649128580 is about 865.8518255126.

The spelling of 649128580 in words is "six hundred forty-nine million, one hundred twenty-eight thousand, five hundred eighty".