81411131 has 8 divisors (see below), whose sum is σ = 82712784. Its totient is φ = 80117280.

The previous prime is 81411107. The next prime is 81411139. The reversal of 81411131 is 13111418.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81411131 is a prime.

It is a super-2 number, since 2×81411131² = 13255544501398322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81411139) 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, 21221 + ... + 24761.

It is an arithmetic number, because the mean of its divisors is an integer number (10339098).

Almost surely, 2^81411131 is an apocalyptic number.

81411131 is a deficient number, since it is larger than the sum of its proper divisors (1301653).

81411131 is a wasteful number, since it uses less digits than its factorization.

81411131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3901.

The product of its digits is 96, while the sum is 20.

The square root of 81411131 is about 9022.8117014598. The cubic root of 81411131 is about 433.4056774022.

Adding to 81411131 its reverse (13111418), we get a palindrome (94522549).

The spelling of 81411131 in words is "eighty-one million, four hundred eleven thousand, one hundred thirty-one".