81618312607008 has 48 divisors (see below), whose sum is σ = 214258429457856. Its totient is φ = 27204788791040.

The previous prime is 81618312606979. The next prime is 81618312607079. The reversal of 81618312607008 is 80070621381618.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18556428 + ... + 22529483.

It is an arithmetic number, because the mean of its divisors is an integer number (4463717280372).

Almost surely, 2^{81618312607008} is an apocalyptic number.

It is an amenable number.

81618312607008 is an abundant number, since it is smaller than the sum of its proper divisors (132640116850848).

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

81618312607008 is a wasteful number, since it uses less digits than its factorization.

81618312607008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41106617 (or 41106609 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 51.

The spelling of 81618312607008 in words is "eighty-one trillion, six hundred eighteen billion, three hundred twelve million, six hundred seven thousand, eight".