647255928 has 128 divisors (see below), whose sum is σ = 1815851520. Its totient is φ = 190594560.

The previous prime is 647255923. The next prime is 647255953. The reversal of 647255928 is 829552746.

647255928 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×647255928² = 837880472662282368, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647255923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2336526 + ... + 2336802.

It is an arithmetic number, because the mean of its divisors is an integer number (14186340).

Almost surely, 2^647255928 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 647255928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907925760).

647255928 is an abundant number, since it is smaller than the sum of its proper divisors (1168595592).

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

647255928 is a wasteful number, since it uses less digits than its factorization.

647255928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 513 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 48.

The square root of 647255928 is about 25441.2249705080. The cubic root of 647255928 is about 865.0184000452.

The spelling of 647255928 in words is "six hundred forty-seven million, two hundred fifty-five thousand, nine hundred twenty-eight".