81108311646 has 32 divisors (see below), whose sum is σ = 163771711488. Its totient is φ = 26778155040.

The previous prime is 81108311629. The next prime is 81108311653. The reversal of 81108311646 is 64611380118.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109731 + ... + 417441.

It is an arithmetic number, because the mean of its divisors is an integer number (5117865984).

Almost surely, 2^81108311646 is an apocalyptic number.

81108311646 is an abundant number, since it is smaller than the sum of its proper divisors (82663399842).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81108311646 is a wasteful number, since it uses less digits than its factorization.

81108311646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308136.

The product of its (nonzero) digits is 27648, while the sum is 39.

The spelling of 81108311646 in words is "eighty-one billion, one hundred eight million, three hundred eleven thousand, six hundred forty-six".