81719 has 16 divisors (see below), whose sum is σ = 103680. Its totient is φ = 63360.

The previous prime is 81707. The next prime is 81727. The reversal of 81719 is 91718.

81719 = 14³ + 15³ + ... + 24³.

It is not a de Polignac number, because 81719 - 2⁴ = 81703 is a prime.

It is a super-2 number, since 2×81719² = 13355989922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3542 + ... + 3564.

It is an arithmetic number, because the mean of its divisors is an integer number (6480).

2⁸¹⁷¹⁹ is an apocalyptic number.

81719 is a deficient number, since it is larger than the sum of its proper divisors (21961).

81719 is a wasteful number, since it uses less digits than its factorization.

81719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70.

The product of its digits is 504, while the sum is 26.

The square root of 81719 is about 285.8653529199. The cubic root of 81719 is about 43.3951320752.

Subtracting 81719 from its reverse (91718), we obtain a palindrome (9999).

The spelling of 81719 in words is "eighty-one thousand, seven hundred nineteen".