81900208601678 has 16 divisors (see below), whose sum is σ = 124934246210160. Its totient is φ = 40255479027456.

The previous prime is 81900208601669. The next prime is 81900208601683. The reversal of 81900208601678 is 87610680200918.

81900208601678 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3859550 + ... + 13367742.

It is an arithmetic number, because the mean of its divisors is an integer number (7808390388135).

Almost surely, 2^{81900208601678} is an apocalyptic number.

81900208601678 is a deficient number, since it is larger than the sum of its proper divisors (43034037608482).

81900208601678 is a wasteful number, since it uses less digits than its factorization.

81900208601678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9581251.

The product of its (nonzero) digits is 2322432, while the sum is 56.

The spelling of 81900208601678 in words is "eighty-one trillion, nine hundred billion, two hundred eight million, six hundred one thousand, six hundred seventy-eight".