81724249456 has 20 divisors (see below), whose sum is σ = 158345179000. Its totient is φ = 40860977472.

The previous prime is 81724249417. The next prime is 81724249459. The reversal of 81724249456 is 65494242718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81724249459) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1015630 + ... + 1093138.

It is an arithmetic number, because the mean of its divisors is an integer number (7917258950).

Almost surely, 2^81724249456 is an apocalyptic number.

It is an amenable number.

81724249456 is a deficient number, since it is larger than the sum of its proper divisors (76620929544).

81724249456 is a wasteful number, since it uses less digits than its factorization.

81724249456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143416 (or 143410 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 52.

The spelling of 81724249456 in words is "eighty-one billion, seven hundred twenty-four million, two hundred forty-nine thousand, four hundred fifty-six".