81133617266 has 32 divisors (see below), whose sum is σ = 132423258240. Its totient is φ = 37057843584.

The previous prime is 81133617259. The next prime is 81133617293. The reversal of 81133617266 is 66271633118.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4326326 + ... + 4345038.

It is an arithmetic number, because the mean of its divisors is an integer number (4138226820).

Almost surely, 2^81133617266 is an apocalyptic number.

81133617266 is a deficient number, since it is larger than the sum of its proper divisors (51289640974).

81133617266 is a wasteful number, since it uses less digits than its factorization.

81133617266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20450.

The product of its digits is 217728, while the sum is 44.

The spelling of 81133617266 in words is "eighty-one billion, one hundred thirty-three million, six hundred seventeen thousand, two hundred sixty-six".