81148393 has 4 divisors (see below), whose sum is σ = 84676608. Its totient is φ = 77620180.

The previous prime is 81148369. The next prime is 81148399. The reversal of 81148393 is 39384118.

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, and also an emirpimes, since its reverse is a distinct semiprime: 39384118 = 2 ⋅19692059.

It is a cyclic number.

It is not a de Polignac number, because 81148393 - 2²⁵ = 47593961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81148399) 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, 1764073 + ... + 1764118.

It is an arithmetic number, because the mean of its divisors is an integer number (21169152).

Almost surely, 2^81148393 is an apocalyptic number.

It is an amenable number.

81148393 is a deficient number, since it is larger than the sum of its proper divisors (3528215).

81148393 is a wasteful number, since it uses less digits than its factorization.

81148393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3528214.

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

The square root of 81148393 is about 9008.2402832074. The cubic root of 81148393 is about 432.9389318055.

The spelling of 81148393 in words is "eighty-one million, one hundred forty-eight thousand, three hundred ninety-three".