81008879616 has 144 divisors (see below), whose sum is σ = 267393016800. Its totient is φ = 23145357312.

The previous prime is 81008879599. The next prime is 81008879629. The reversal of 81008879616 is 61697880018.

81008879616 is a `hidden beast` number, since 8 + 10 + 0 + 8 + 8 + 7 + 9 + 616 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 184906 + ... + 442953.

It is an arithmetic number, because the mean of its divisors is an integer number (1856895950).

Almost surely, 2^81008879616 is an apocalyptic number.

It is an amenable number.

81008879616 is an abundant number, since it is smaller than the sum of its proper divisors (186384137184).

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

81008879616 is a wasteful number, since it uses less digits than its factorization.

81008879616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 627894 (or 627871 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 54.

The spelling of 81008879616 in words is "eighty-one billion, eight million, eight hundred seventy-nine thousand, six hundred sixteen".