81755015424 has 72 divisors (see below), whose sum is σ = 227047945152. Its totient is φ = 26066810880.

The previous prime is 81755015423. The next prime is 81755015473. The reversal of 81755015424 is 42451055718.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81755015423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2296507 + ... + 2331834.

Almost surely, 2^81755015424 is an apocalyptic number.

It is an amenable number.

81755015424 is an abundant number, since it is smaller than the sum of its proper divisors (145292929728).

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

81755015424 is a wasteful number, since it uses less digits than its factorization.

81755015424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4628383 (or 4628369 counting only the distinct ones).

The product of its (nonzero) digits is 224000, while the sum is 42.

The spelling of 81755015424 in words is "eighty-one billion, seven hundred fifty-five million, fifteen thousand, four hundred twenty-four".