81347719 has 8 divisors (see below), whose sum is σ = 84556080. Its totient is φ = 78192576.

The previous prime is 81347699. The next prime is 81347743. The reversal of 81347719 is 91774318.

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 81347719 - 2⁵ = 81347687 is a prime.

It is a super-2 number, since 2×81347719² = 13234902773005922, 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 (81347779) 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, 10174 + ... + 16315.

It is an arithmetic number, because the mean of its divisors is an integer number (10569510).

Almost surely, 2^81347719 is an apocalyptic number.

81347719 is a deficient number, since it is larger than the sum of its proper divisors (3208361).

81347719 is a wasteful number, since it uses less digits than its factorization.

81347719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26609.

The product of its digits is 42336, while the sum is 40.

The square root of 81347719 is about 9019.2970346918. The cubic root of 81347719 is about 433.2931200685.

The spelling of 81347719 in words is "eighty-one million, three hundred forty-seven thousand, seven hundred nineteen".