81363213305 has 64 divisors (see below), whose sum is σ = 113408294400. Its totient is φ = 55468062720.

The previous prime is 81363213263. The next prime is 81363213311. The reversal of 81363213305 is 50331236318.

It is a happy number.

It is not a de Polignac number, because 81363213305 - 2¹⁶ = 81363147769 is a prime.

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 63 ways as a sum of consecutive naturals, for example, 33578324 + ... + 33580746.

It is an arithmetic number, because the mean of its divisors is an integer number (1772004600).

Almost surely, 2^81363213305 is an apocalyptic number.

It is an amenable number.

81363213305 is a deficient number, since it is larger than the sum of its proper divisors (32045081095).

81363213305 is a wasteful number, since it uses less digits than its factorization.

81363213305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3074.

The product of its (nonzero) digits is 38880, while the sum is 35.

The spelling of 81363213305 in words is "eighty-one billion, three hundred sixty-three million, two hundred thirteen thousand, three hundred five".