81134681 has 4 divisors (see below), whose sum is σ = 81153792. Its totient is φ = 81115572.

The previous prime is 81134653. The next prime is 81134701. The reversal of 81134681 is 18643118.

It is a happy number.

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 81134681 - 2²² = 76940377 is a prime.

It is a super-2 number, since 2×81134681² = 13165672921943522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81134621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5 + ... + 12738.

It is an arithmetic number, because the mean of its divisors is an integer number (20288448).

Almost surely, 2^81134681 is an apocalyptic number.

It is an amenable number.

81134681 is a deficient number, since it is larger than the sum of its proper divisors (19111).

81134681 is a wasteful number, since it uses less digits than its factorization.

81134681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19110.

The product of its digits is 4608, while the sum is 32.

The square root of 81134681 is about 9007.4791701119. The cubic root of 81134681 is about 432.9145452349.

Adding to 81134681 its reverse (18643118), we get a palindrome (99777799).

The spelling of 81134681 in words is "eighty-one million, one hundred thirty-four thousand, six hundred eighty-one".