81535941 has 12 divisors (see below), whose sum is σ = 118817868. Its totient is φ = 53875584.

The previous prime is 81535939. The next prime is 81535957. The reversal of 81535941 is 14953518.

81535941 is a `hidden beast` number, since 81 + 535 + 9 + 41 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7403841 + 74132100 = 2721^2 + 8610^2 .

It is not a de Polignac number, because 81535941 - 2¹ = 81535939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81535896 and 81535905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81535931) 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 11 ways as a sum of consecutive naturals, for example, 39070 + ... + 41103.

It is an arithmetic number, because the mean of its divisors is an integer number (9901489).

Almost surely, 2^81535941 is an apocalyptic number.

It is an amenable number.

81535941 is a deficient number, since it is larger than the sum of its proper divisors (37281927).

81535941 is a wasteful number, since it uses less digits than its factorization.

81535941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80292 (or 80289 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 81535941 is about 9029.7254111075. The cubic root of 81535941 is about 433.6270465699.

The spelling of 81535941 in words is "eighty-one million, five hundred thirty-five thousand, nine hundred forty-one".