647650640 has 240 divisors, whose sum is σ = 1923626880. Its totient is φ = 200954880.

The previous prime is 647650639. The next prime is 647650643. The reversal of 647650640 is 46056746.

It is a junction number, because it is equal to n+sod(n) for n = 647650594 and 647650603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647650643) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3618071 + ... + 3618249.

It is an arithmetic number, because the mean of its divisors is an integer number (8015112).

Almost surely, 2^647650640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647650640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (961813440).

647650640 is an abundant number, since it is smaller than the sum of its proper divisors (1275976240).

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

647650640 is a wasteful number, since it uses less digits than its factorization.

647650640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 38.

The square root of 647650640 is about 25448.9811190939. The cubic root of 647650640 is about 865.1942005525.

The spelling of 647650640 in words is "six hundred forty-seven million, six hundred fifty thousand, six hundred forty".