646082778 has 16 divisors (see below), whose sum is σ = 1409635296. Its totient is φ = 195782640.

The previous prime is 646082737. The next prime is 646082791. The reversal of 646082778 is 877280646.

It is an unprimeable number.

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, 4894501 + ... + 4894632.

It is an arithmetic number, because the mean of its divisors is an integer number (88102206).

Almost surely, 2^646082778 is an apocalyptic number.

646082778 is an abundant number, since it is smaller than the sum of its proper divisors (763552518).

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

646082778 is a wasteful number, since it uses less digits than its factorization.

646082778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9789149.

The product of its (nonzero) digits is 903168, while the sum is 48.

The square root of 646082778 is about 25418.1584305394. The cubic root of 646082778 is about 864.4954693076.

The spelling of 646082778 in words is "six hundred forty-six million, eighty-two thousand, seven hundred seventy-eight".