81411517 has 4 divisors (see below), whose sum is σ = 88812576. Its totient is φ = 74010460.

The previous prime is 81411503. The next prime is 81411529. The reversal of 81411517 is 71511418.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81411517 - 2¹⁵ = 81378749 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 (81411557) 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 3 ways as a sum of consecutive naturals, for example, 3700513 + ... + 3700534.

It is an arithmetic number, because the mean of its divisors is an integer number (22203144).

Almost surely, 2^81411517 is an apocalyptic number.

It is an amenable number.

81411517 is a deficient number, since it is larger than the sum of its proper divisors (7401059).

81411517 is a wasteful number, since it uses less digits than its factorization.

81411517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7401058.

The product of its digits is 1120, while the sum is 28.

The square root of 81411517 is about 9022.8330916625. The cubic root of 81411517 is about 433.4063623795.

Subtracting from 81411517 its reverse (71511418), we obtain a palindrome (9900099).

The spelling of 81411517 in words is "eighty-one million, four hundred eleven thousand, five hundred seventeen".