647128046520 has 192 divisors, whose sum is σ = 2156570226720. Its totient is φ = 168238743552.

The previous prime is 647128046443. The next prime is 647128046557. The reversal of 647128046520 is 25640821746.

647128046520 is a `hidden beast` number, since 6 + 4 + 7 + 1 + 2 + 80 + 46 + 520 = 666.

It is a super-2 number, since 2×647128046520² (a number of 24 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2201344 + ... + 2477936.

Almost surely, 2^647128046520 is an apocalyptic number.

647128046520 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 647128046520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1078285113360).

647128046520 is an abundant number, since it is smaller than the sum of its proper divisors (1509442180200).

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

647128046520 is a wasteful number, since it uses less digits than its factorization.

647128046520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276774 (or 276767 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 647128046520 in words is "six hundred forty-seven billion, one hundred twenty-eight million, forty-six thousand, five hundred twenty".