81724862115 has 56 divisors (see below), whose sum is σ = 158348156400. Its totient is φ = 40233754944.

The previous prime is 81724862099. The next prime is 81724862123. The reversal of 81724862115 is 51126842718.

81724862115 is a `hidden beast` number, since 8 + 1 + 7 + 2 + 4 + 8 + 621 + 15 = 666.

It is not a de Polignac number, because 81724862115 - 2⁴ = 81724862099 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 55 ways as a sum of consecutive naturals, for example, 814965 + ... + 909734.

It is an arithmetic number, because the mean of its divisors is an integer number (2827645650).

Almost surely, 2^81724862115 is an apocalyptic number.

81724862115 is a deficient number, since it is larger than the sum of its proper divisors (76623294285).

81724862115 is a wasteful number, since it uses less digits than its factorization.

81724862115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1724735 (or 1724720 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The spelling of 81724862115 in words is "eighty-one billion, seven hundred twenty-four million, eight hundred sixty-two thousand, one hundred fifteen".