81355343 has 4 divisors (see below), whose sum is σ = 81376248. Its totient is φ = 81334440.

The previous prime is 81355331. The next prime is 81355349. The reversal of 81355343 is 34355318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34355318 = 2 ⋅17177659.

It is a cyclic number.

It is not a de Polignac number, because 81355343 - 2¹⁰ = 81354319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81355349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2696 + ... + 13037.

It is an arithmetic number, because the mean of its divisors is an integer number (20344062).

Almost surely, 2^81355343 is an apocalyptic number.

81355343 is a deficient number, since it is larger than the sum of its proper divisors (20905).

81355343 is a wasteful number, since it uses less digits than its factorization.

81355343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20904.

The product of its digits is 21600, while the sum is 32.

The square root of 81355343 is about 9019.7196741362. The cubic root of 81355343 is about 433.3066558856.

The spelling of 81355343 in words is "eighty-one million, three hundred fifty-five thousand, three hundred forty-three".