81063863021 has 16 divisors (see below), whose sum is σ = 84362784768. Its totient is φ = 77841936000.

The previous prime is 81063863011. The next prime is 81063863051. The reversal of 81063863021 is 12036836018.

It is a cyclic number.

It is not a de Polignac number, because 81063863021 - 2³⁴ = 63883993837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81063863011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 593471 + ... + 717171.

It is an arithmetic number, because the mean of its divisors is an integer number (5272674048).

Almost surely, 2^81063863021 is an apocalyptic number.

It is an amenable number.

81063863021 is a deficient number, since it is larger than the sum of its proper divisors (3298921747).

81063863021 is a wasteful number, since it uses less digits than its factorization.

81063863021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124012.

The product of its (nonzero) digits is 41472, while the sum is 38.

The spelling of 81063863021 in words is "eighty-one billion, sixty-three million, eight hundred sixty-three thousand, twenty-one".