81682719519 has 8 divisors (see below), whose sum is σ = 114642413440. Its totient is φ = 51589085976.

The previous prime is 81682719493. The next prime is 81682719551. The reversal of 81682719519 is 91591728618.

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

It is not a de Polignac number, because 81682719519 - 2⁵ = 81682719487 is a prime.

It is a super-2 number, since 2×81682719519² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 1433030167 = 81682719519 / (8 + 1 + 6 + 8 + 2 + 7 + 1 + 9 + 5 + 1 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81682719589) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 716515027 + ... + 716515140.

It is an arithmetic number, because the mean of its divisors is an integer number (14330301680).

Almost surely, 2^81682719519 is an apocalyptic number.

81682719519 is a deficient number, since it is larger than the sum of its proper divisors (32959693921).

81682719519 is a wasteful number, since it uses less digits than its factorization.

81682719519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433030189.

The product of its digits is 2177280, while the sum is 57.

Subtracting 81682719519 from its reverse (91591728618), we obtain a palindrome (9909009099).

The spelling of 81682719519 in words is "eighty-one billion, six hundred eighty-two million, seven hundred nineteen thousand, five hundred nineteen".