81812141 has 4 divisors (see below), whose sum is σ = 81896352. Its totient is φ = 81727932.

The previous prime is 81812117. The next prime is 81812147. The reversal of 81812141 is 14121818.

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, and also an emirpimes, since its reverse is a distinct semiprime: 14121818 = 2 ⋅7060909.

It is a cyclic number.

It is not a de Polignac number, because 81812141 - 2¹⁴ = 81795757 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81812141.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81812147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40631 + ... + 42596.

It is an arithmetic number, because the mean of its divisors is an integer number (20474088).

Almost surely, 2^81812141 is an apocalyptic number.

It is an amenable number.

81812141 is a deficient number, since it is larger than the sum of its proper divisors (84211).

81812141 is an equidigital number, since it uses as much as digits as its factorization.

81812141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84210.

The product of its digits is 512, while the sum is 26.

The square root of 81812141 is about 9045.0064123803. The cubic root of 81812141 is about 434.1161266263.

Adding to 81812141 its reverse (14121818), we get a palindrome (95933959).

The spelling of 81812141 in words is "eighty-one million, eight hundred twelve thousand, one hundred forty-one".