81842841 has 12 divisors (see below), whose sum is σ = 119082132. Its totient is φ = 54162816.

The previous prime is 81842833. The next prime is 81842863. The reversal of 81842841 is 14824818.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 65610000 + 16232841 = 8100^2 + 4029^2 .

It is not a de Polignac number, because 81842841 - 2³ = 81842833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81842796 and 81842805.

It is not an unprimeable number, because it can be changed into a prime (81842801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31956 + ... + 34421.

It is an arithmetic number, because the mean of its divisors is an integer number (9923511).

Almost surely, 2^81842841 is an apocalyptic number.

It is an amenable number.

81842841 is a deficient number, since it is larger than the sum of its proper divisors (37239291).

81842841 is a wasteful number, since it uses less digits than its factorization.

81842841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66520 (or 66517 counting only the distinct ones).

The product of its digits is 16384, while the sum is 36.

The square root of 81842841 is about 9046.7033222053. The cubic root of 81842841 is about 434.1704205173.

It can be divided in two parts, 8184 and 2841, that added together give a square (11025 = 105²).

The spelling of 81842841 in words is "eighty-one million, eight hundred forty-two thousand, eight hundred forty-one".