647705240 has 128 divisors (see below), whose sum is σ = 1811496960. Its totient is φ = 202950144.

The previous prime is 647705221. The next prime is 647705291. The reversal of 647705240 is 42507746.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 647705240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 388649 + ... + 390311.

It is an arithmetic number, because the mean of its divisors is an integer number (14152320).

Almost surely, 2^647705240 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 647705240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (905748480).

647705240 is an abundant number, since it is smaller than the sum of its proper divisors (1163791720).

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

647705240 is a wasteful number, since it uses less digits than its factorization.

647705240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801 (or 1797 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 35.

The square root of 647705240 is about 25450.0538309843. The cubic root of 647705240 is about 865.2185131850.

The spelling of 647705240 in words is "six hundred forty-seven million, seven hundred five thousand, two hundred forty".