81724556415 has 48 divisors (see below), whose sum is σ = 134523607680. Its totient is φ = 42365911680.

The previous prime is 81724556371. The next prime is 81724556429. The reversal of 81724556415 is 51465542718.

It is a happy number.

It is not a de Polignac number, because 81724556415 - 2²⁴ = 81707779199 is a prime.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 40637760 + ... + 40639770.

It is an arithmetic number, because the mean of its divisors is an integer number (2802575160).

Almost surely, 2^81724556415 is an apocalyptic number.

81724556415 is a deficient number, since it is larger than the sum of its proper divisors (52799051265).

81724556415 is a wasteful number, since it uses less digits than its factorization.

81724556415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4072 (or 4035 counting only the distinct ones).

The product of its digits is 1344000, while the sum is 48.

The spelling of 81724556415 in words is "eighty-one billion, seven hundred twenty-four million, five hundred fifty-six thousand, four hundred fifteen".