647749856 has 24 divisors (see below), whose sum is σ = 1373355144. Its totient is φ = 298961280.

The previous prime is 647749853. The next prime is 647749877. The reversal of 647749856 is 658947746.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647749853) 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, 778130 + ... + 778961.

It is an arithmetic number, because the mean of its divisors is an integer number (57223131).

Almost surely, 2^647749856 is an apocalyptic number.

It is an amenable number.

647749856 is an abundant number, since it is smaller than the sum of its proper divisors (725605288).

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

647749856 is a wasteful number, since it uses less digits than its factorization.

647749856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557114 (or 1557106 counting only the distinct ones).

The product of its digits is 10160640, while the sum is 56.

The square root of 647749856 is about 25450.9303562758. The cubic root of 647749856 is about 865.2383790645.

The spelling of 647749856 in words is "six hundred forty-seven million, seven hundred forty-nine thousand, eight hundred fifty-six".