81047549784 has 64 divisors (see below), whose sum is σ = 212477176800. Its totient is φ = 25726934016.

The previous prime is 81047549783. The next prime is 81047549833. The reversal of 81047549784 is 48794574018.

It is a hoax number, since the sum of its digits (57) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81047549783) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 746779 + ... + 848394.

Almost surely, 2^81047549784 is an apocalyptic number.

It is an amenable number.

81047549784 is an abundant number, since it is smaller than the sum of its proper divisors (131429627016).

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

81047549784 is a wasteful number, since it uses less digits than its factorization.

81047549784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1595284 (or 1595280 counting only the distinct ones).

The product of its (nonzero) digits is 9031680, while the sum is 57.

The spelling of 81047549784 in words is "eighty-one billion, forty-seven million, five hundred forty-nine thousand, seven hundred eighty-four".