643078235728 has 40 divisors (see below), whose sum is σ = 1265310979200. Its totient is φ = 316569437184.

The previous prime is 643078235711. The next prime is 643078235797. The reversal of 643078235728 is 827532870346.

It is a happy number.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274438 + ... + 1166821.

It is an arithmetic number, because the mean of its divisors is an integer number (31632774480).

Almost surely, 2^643078235728 is an apocalyptic number.

It is an amenable number.

643078235728 is a deficient number, since it is larger than the sum of its proper divisors (622232743472).

643078235728 is a wasteful number, since it uses less digits than its factorization.

643078235728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1441699 (or 1441693 counting only the distinct ones).

The product of its (nonzero) digits is 13547520, while the sum is 55.

The spelling of 643078235728 in words is "six hundred forty-three billion, seventy-eight million, two hundred thirty-five thousand, seven hundred twenty-eight".