81355743 has 24 divisors (see below), whose sum is σ = 135696288. Its totient is φ = 46006272.

The previous prime is 81355741. The next prime is 81355751. The reversal of 81355743 is 34755318.

81355743 is a `hidden beast` number, since 81 + 3 + 5 + 574 + 3 = 666.

It is not a de Polignac number, because 81355743 - 2¹ = 81355741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81355698 and 81355707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81355741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 546 + ... + 12767.

It is an arithmetic number, because the mean of its divisors is an integer number (5654012).

Almost surely, 2^81355743 is an apocalyptic number.

81355743 is a deficient number, since it is larger than the sum of its proper divisors (54340545).

81355743 is a wasteful number, since it uses less digits than its factorization.

81355743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13423 (or 13420 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 81355743 is about 9019.7418477471. The cubic root of 81355743 is about 433.3073660311.

The spelling of 81355743 in words is "eighty-one million, three hundred fifty-five thousand, seven hundred forty-three".