646617358356480 has 5616 divisors, whose sum is σ = 2947550224029840. Its totient is φ = 135227523465216.

The previous prime is 646617358356467. The next prime is 646617358356583. The reversal of 646617358356480 is 84653853716646.

646617358356480 is a `hidden beast` number, since 6 + 4 + 6 + 6 + 1 + 7 + 3 + 58 + 3 + 564 + 8 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 53731480190976 + 592885878165504 = 7330176^2 + 24349248^2 .

It is a super-2 number, since 2×646617358356480² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 646617358356399 and 646617358356408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 5932269342666 + ... + 5932269342774.

It is an arithmetic number, because the mean of its divisors is an integer number (524848686615).

Almost surely, 2^{646617358356480} is an apocalyptic number.

646617358356480 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 646617358356480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1473775112014920).

646617358356480 is an abundant number, since it is smaller than the sum of its proper divisors (2300932865673360).

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

646617358356480 is an equidigital number, since it uses as much as digits as its factorization.

646617358356480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 2090188800, while the sum is 72.

The spelling of 646617358356480 in words is "six hundred forty-six trillion, six hundred seventeen billion, three hundred fifty-eight million, three hundred fifty-six thousand, four hundred eighty".