81228938810997 has 32 divisors (see below), whose sum is σ = 111866749263360. Its totient is φ = 52400406732800.

The previous prime is 81228938810959. The next prime is 81228938811001. The reversal of 81228938810997 is 79901883982218.

It is a cyclic number.

It is not a de Polignac number, because 81228938810997 - 2³² = 81224643843701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81228938810297) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32329 + ... + 12745937.

It is an arithmetic number, because the mean of its divisors is an integer number (3495835914480).

Almost surely, 2^{81228938810997} is an apocalyptic number.

It is an amenable number.

81228938810997 is a deficient number, since it is larger than the sum of its proper divisors (30637810452363).

81228938810997 is a wasteful number, since it uses less digits than its factorization.

81228938810997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12714173.

The product of its (nonzero) digits is 250822656, while the sum is 75.

The spelling of 81228938810997 in words is "eighty-one trillion, two hundred twenty-eight billion, nine hundred thirty-eight million, eight hundred ten thousand, nine hundred ninety-seven".