81819343 has 4 divisors (see below), whose sum is σ = 81840528. Its totient is φ = 81798160.

The previous prime is 81819341. The next prime is 81819359. The reversal of 81819343 is 34391818.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34391818 = 2 ⋅17195909.

It is a cyclic number.

It is not a de Polignac number, because 81819343 - 2¹ = 81819341 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 (81819341) 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, 2971 + ... + 13132.

It is an arithmetic number, because the mean of its divisors is an integer number (20460132).

Almost surely, 2^81819343 is an apocalyptic number.

81819343 is a deficient number, since it is larger than the sum of its proper divisors (21185).

81819343 is a wasteful number, since it uses less digits than its factorization.

81819343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21184.

The product of its digits is 20736, while the sum is 37.

The square root of 81819343 is about 9045.4045238452. The cubic root of 81819343 is about 434.1288648033.

The spelling of 81819343 in words is "eighty-one million, eight hundred nineteen thousand, three hundred forty-three".