647720740 has 48 divisors (see below), whose sum is σ = 1444755312. Its totient is φ = 243081216.

The previous prime is 647720707. The next prime is 647720767. The reversal of 647720740 is 47027746.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7529536 + 640191204 = 2744^2 + 25302^2 .

It is a super-2 number, since 2×647720740² = 839084314052295200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 647720740.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111754 + ... + 117406.

It is an arithmetic number, because the mean of its divisors is an integer number (30099069).

Almost surely, 2^647720740 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 647720740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722377656).

647720740 is an abundant number, since it is smaller than the sum of its proper divisors (797034572).

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

647720740 is a wasteful number, since it uses less digits than its factorization.

647720740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6016 (or 6014 counting only the distinct ones).

The product of its (nonzero) digits is 65856, while the sum is 37.

The square root of 647720740 is about 25450.3583471825. The cubic root of 647720740 is about 865.2254148738.

The spelling of 647720740 in words is "six hundred forty-seven million, seven hundred twenty thousand, seven hundred forty".