647815680 has 240 divisors, whose sum is σ = 2318494464. Its totient is φ = 166993920.

The previous prime is 647815673. The next prime is 647815681. The reversal of 647815680 is 86518746.

It is a happy number.

647815680 is a `hidden beast` number, since 6 + 4 + 7 + 81 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (647815681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 713787 + ... + 714693.

Almost surely, 2^647815680 is an apocalyptic number.

647815680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647815680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1159247232).

647815680 is an abundant number, since it is smaller than the sum of its proper divisors (1670678784).

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

647815680 is a wasteful number, since it uses less digits than its factorization.

647815680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967 (or 948 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 647815680 is about 25452.2234785097. The cubic root of 647815680 is about 865.2676864283.

The spelling of 647815680 in words is "six hundred forty-seven million, eight hundred fifteen thousand, six hundred eighty".