646646626080 has 2880 divisors, whose sum is σ = 3079049228640. Its totient is φ = 126414618624.

The previous prime is 646646626039. The next prime is 646646626099. The reversal of 646646626080 is 80626646646.

646646626080 is a `hidden beast` number, since 6 + 4 + 6 + 6 + 4 + 6 + 626 + 0 + 8 + 0 = 666.

It can be written as a sum of positive squares in 16 ways, for example, as 98116791696 + 548529834384 = 313236^2 + 740628^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 8858172924 + ... + 8858172996.

Almost surely, 2^646646626080 is an apocalyptic number.

646646626080 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 646646626080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1539524614320).

646646626080 is an abundant number, since it is smaller than the sum of its proper divisors (2432402602560).

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

646646626080 is a wasteful number, since it uses less digits than its factorization.

646646626080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 11943936, while the sum is 54.

The spelling of 646646626080 in words is "six hundred forty-six billion, six hundred forty-six million, six hundred twenty-six thousand, eighty".