81000904648 has 16 divisors (see below), whose sum is σ = 156775944960. Its totient is φ = 39193986000.

The previous prime is 81000904639. The next prime is 81000904687. The reversal of 81000904648 is 84640900018.

It is a super-2 number, since 2×81000904648² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81000904648.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163308028 + ... + 163308523.

It is an arithmetic number, because the mean of its divisors is an integer number (9798496560).

Almost surely, 2^81000904648 is an apocalyptic number.

It is an amenable number.

81000904648 is a deficient number, since it is larger than the sum of its proper divisors (75775040312).

81000904648 is a wasteful number, since it uses less digits than its factorization.

81000904648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326616588 (or 326616584 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 81000904648 in words is "eighty-one billion, nine hundred four thousand, six hundred forty-eight".