646916080 has 80 divisors (see below), whose sum is σ = 1557087840. Its totient is φ = 249790464.

The previous prime is 646916077. The next prime is 646916089. The reversal of 646916080 is 80619646.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646916089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 305104 + ... + 307216.

It is an arithmetic number, because the mean of its divisors is an integer number (19463598).

Almost surely, 2^646916080 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646916080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (778543920).

646916080 is an abundant number, since it is smaller than the sum of its proper divisors (910171760).

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

646916080 is a wasteful number, since it uses less digits than its factorization.

646916080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2258 (or 2252 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 646916080 is about 25434.5450126398. The cubic root of 646916080 is about 864.8669781079.

The spelling of 646916080 in words is "six hundred forty-six million, nine hundred sixteen thousand, eighty".