650778640 has 20 divisors (see below), whose sum is σ = 1513060524. Its totient is φ = 260311424.

The previous prime is 650778631. The next prime is 650778643. The reversal of 650778640 is 46877056.

It can be written as a sum of positive squares in 2 ways, for example, as 118461456 + 532317184 = 10884^2 + 23072^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (650778643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4067287 + ... + 4067446.

Almost surely, 2^650778640 is an apocalyptic number.

It is an amenable number.

650778640 is an abundant number, since it is smaller than the sum of its proper divisors (862281884).

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

650778640 is a wasteful number, since it uses less digits than its factorization.

650778640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8134746 (or 8134740 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 43.

The square root of 650778640 is about 25510.3633843189. The cubic root of 650778640 is about 866.5848588133.

The spelling of 650778640 in words is "six hundred fifty million, seven hundred seventy-eight thousand, six hundred forty".