616721640868 has 12 divisors (see below), whose sum is σ = 1088813871180. Its totient is φ = 305631963392.

The previous prime is 616721640859. The next prime is 616721640907. The reversal of 616721640868 is 868046127616.

It can be written as a sum of positive squares in 2 ways, for example, as 152418406464 + 464303234404 = 390408^2 + 681398^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 682213753 + ... + 682214656.

It is an arithmetic number, because the mean of its divisors is an integer number (90734489265).

Almost surely, 2^616721640868 is an apocalyptic number.

It is an amenable number.

616721640868 is a deficient number, since it is larger than the sum of its proper divisors (472092230312).

616721640868 is a wasteful number, since it uses less digits than its factorization.

616721640868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364428526 (or 1364428524 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 55.

The spelling of 616721640868 in words is "six hundred sixteen billion, seven hundred twenty-one million, six hundred forty thousand, eight hundred sixty-eight".