647256564 has 108 divisors (see below), whose sum is σ = 1727379108. Its totient is φ = 204272640.

The previous prime is 647256563. The next prime is 647256569. The reversal of 647256564 is 465652746.

647256564 is a `hidden beast` number, since 64 + 7 + 25 + 6 + 564 = 666.

647256564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 367028964 + 280227600 = 19158^2 + 16740^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647256563) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1833412 + ... + 1833764.

It is an arithmetic number, because the mean of its divisors is an integer number (15994251).

Almost surely, 2^647256564 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 647256564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (863689554).

647256564 is an abundant number, since it is smaller than the sum of its proper divisors (1080122544).

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

647256564 is a wasteful number, since it uses less digits than its factorization.

647256564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 442 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 45.

The square root of 647256564 is about 25441.2374699031. The cubic root of 647256564 is about 865.0186833703.

It can be divided in two parts, 64725 and 6564, that added together give a square (71289 = 267²).

The spelling of 647256564 in words is "six hundred forty-seven million, two hundred fifty-six thousand, five hundred sixty-four".