81959543 has 8 divisors (see below), whose sum is σ = 82992000. Its totient is φ = 80933688.

The previous prime is 81959513. The next prime is 81959569. The reversal of 81959543 is 34595918.

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 not a de Polignac number, because 81959543 - 2²⁶ = 14850679 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81959494 and 81959503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81959503) 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, 26180 + ... + 29142.

It is an arithmetic number, because the mean of its divisors is an integer number (10374000).

Almost surely, 2^81959543 is an apocalyptic number.

81959543 is a deficient number, since it is larger than the sum of its proper divisors (1032457).

81959543 is a wasteful number, since it uses less digits than its factorization.

81959543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3301.

The product of its digits is 194400, while the sum is 44.

The square root of 81959543 is about 9053.1509984093. The cubic root of 81959543 is about 434.3766877632.

The spelling of 81959543 in words is "eighty-one million, nine hundred fifty-nine thousand, five hundred forty-three".