646704414720 has 2520 divisors, whose sum is σ = 3086622302904. Its totient is φ = 128421199872.

The previous prime is 646704414709. The next prime is 646704414743. The reversal of 646704414720 is 27414407646.

It is a happy number.

646704414720 is a `hidden beast` number, since 6 + 467 + 0 + 44 + 147 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 47405481984 + 599298932736 = 217728^2 + 774144^2 .

It is a tau number, because it is divible by the number of its divisors (2520).

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 polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 38041436152 + ... + 38041436168.

Almost surely, 2^646704414720 is an apocalyptic number.

646704414720 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 646704414720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1543311151452).

646704414720 is an abundant number, since it is smaller than the sum of its proper divisors (2439917888184).

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

646704414720 is an equidigital number, since it uses as much as digits as its factorization.

646704414720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 903168, while the sum is 45.

The spelling of 646704414720 in words is "six hundred forty-six billion, seven hundred four million, four hundred fourteen thousand, seven hundred twenty".