81411071 has 4 divisors (see below), whose sum is σ = 93041232. Its totient is φ = 69780912.

The previous prime is 81411047. The next prime is 81411089. The reversal of 81411071 is 17011418.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17011418 = 2 ⋅8505709.

It is a cyclic number.

It is not a de Polignac number, because 81411071 - 2¹⁸ = 81148927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81411871) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5815070 + ... + 5815083.

It is an arithmetic number, because the mean of its divisors is an integer number (23260308).

Almost surely, 2^81411071 is an apocalyptic number.

81411071 is a deficient number, since it is larger than the sum of its proper divisors (11630161).

81411071 is a wasteful number, since it uses less digits than its factorization.

81411071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11630160.

The product of its (nonzero) digits is 224, while the sum is 23.

The square root of 81411071 is about 9022.8083765533. The cubic root of 81411071 is about 433.4055709289.

Adding to 81411071 its reverse (17011418), we get a palindrome (98422489).

The spelling of 81411071 in words is "eighty-one million, four hundred eleven thousand, seventy-one".