81844793 has 4 divisors (see below), whose sum is σ = 82001808. Its totient is φ = 81687780.

The previous prime is 81844771. The next prime is 81844801. The reversal of 81844793 is 39744818.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81844793 - 2⁸ = 81844537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81844393) 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 3 ways as a sum of consecutive naturals, for example, 77723 + ... + 78768.

It is an arithmetic number, because the mean of its divisors is an integer number (20500452).

Almost surely, 2^81844793 is an apocalyptic number.

It is an amenable number.

81844793 is a deficient number, since it is larger than the sum of its proper divisors (157015).

81844793 is a wasteful number, since it uses less digits than its factorization.

81844793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157014.

The product of its digits is 193536, while the sum is 44.

The square root of 81844793 is about 9046.8112061654. The cubic root of 81844793 is about 434.1738722300.

The spelling of 81844793 in words is "eighty-one million, eight hundred forty-four thousand, seven hundred ninety-three".