81228657966 has 16 divisors (see below), whose sum is σ = 164682759504. Its totient is φ = 26705312064.

The previous prime is 81228657947. The next prime is 81228658079. The reversal of 81228657966 is 66975682218.

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, 92726341 + ... + 92727216.

It is an arithmetic number, because the mean of its divisors is an integer number (10292672469).

Almost surely, 2^81228657966 is an apocalyptic number.

81228657966 is an abundant number, since it is smaller than the sum of its proper divisors (83454101538).

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

81228657966 is a wasteful number, since it uses less digits than its factorization.

81228657966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185453635.

The product of its digits is 17418240, while the sum is 60.

The spelling of 81228657966 in words is "eighty-one billion, two hundred twenty-eight million, six hundred fifty-seven thousand, nine hundred sixty-six".