81896438736 has 60 divisors (see below), whose sum is σ = 261938612832. Its totient is φ = 23398982208.

The previous prime is 81896438719. The next prime is 81896438759. The reversal of 81896438736 is 63783469818.

81896438736 is a `hidden beast` number, since 81 + 8 + 96 + 438 + 7 + 36 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 40622226 + ... + 40624241.

Almost surely, 2^81896438736 is an apocalyptic number.

It is an amenable number.

81896438736 is an abundant number, since it is smaller than the sum of its proper divisors (180042174096).

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

81896438736 is a wasteful number, since it uses less digits than its factorization.

81896438736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81246488 (or 81246479 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 63.

The spelling of 81896438736 in words is "eighty-one billion, eight hundred ninety-six million, four hundred thirty-eight thousand, seven hundred thirty-six".