81744719 has 8 divisors (see below), whose sum is σ = 94018848. Its totient is φ = 69619680.

The previous prime is 81744701. The next prime is 81744731. The reversal of 81744719 is 91744718.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81744719 - 2⁸ = 81744463 is a prime.

It is a super-2 number, since 2×81744719² = 13364398168777922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81744739) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 36092 + ... + 38289.

It is an arithmetic number, because the mean of its divisors is an integer number (11752356).

Almost surely, 2^81744719 is an apocalyptic number.

81744719 is a deficient number, since it is larger than the sum of its proper divisors (12274129).

81744719 is a wasteful number, since it uses less digits than its factorization.

81744719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74545.

The product of its digits is 56448, while the sum is 41.

The square root of 81744719 is about 9041.2786153287. The cubic root of 81744719 is about 433.9968410652.

Subtracting 81744719 from its reverse (91744718), we obtain a palindrome (9999999).

The spelling of 81744719 in words is "eighty-one million, seven hundred forty-four thousand, seven hundred nineteen".