81071217612 has 144 divisors (see below), whose sum is σ = 264307680000. Its totient is φ = 20331319680.

The previous prime is 81071217607. The next prime is 81071217637. The reversal of 81071217612 is 21671217018.

81071217612 is a `hidden beast` number, since 8 + 10 + 7 + 1 + 21 + 7 + 612 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 47 ways as a sum of consecutive naturals, for example, 423862 + ... + 584637.

It is an arithmetic number, because the mean of its divisors is an integer number (1835470000).

Almost surely, 2^81071217612 is an apocalyptic number.

It is an amenable number.

81071217612 is an abundant number, since it is smaller than the sum of its proper divisors (183236462388).

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

81071217612 is a wasteful number, since it uses less digits than its factorization.

81071217612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1008556 (or 1008551 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 36.

The spelling of 81071217612 in words is "eighty-one billion, seventy-one million, two hundred seventeen thousand, six hundred twelve".