646860080 has 40 divisors (see below), whose sum is σ = 1555815600. Its totient is φ = 249820928.

The previous prime is 646860079. The next prime is 646860089. The reversal of 646860080 is 80068646.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (646860089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137090 + ... + 141729.

It is an arithmetic number, because the mean of its divisors is an integer number (38895390).

Almost surely, 2^646860080 is an apocalyptic number.

It is an amenable number.

646860080 is an abundant number, since it is smaller than the sum of its proper divisors (908955520).

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

646860080 is a wasteful number, since it uses less digits than its factorization.

646860080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278861 (or 278855 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 646860080 is about 25433.4441238303. Note that the first 3 decimals coincide. The cubic root of 646860080 is about 864.8420217805.

The spelling of 646860080 in words is "six hundred forty-six million, eight hundred sixty thousand, eighty".