81348149 has 4 divisors (see below), whose sum is σ = 81769836. Its totient is φ = 80926464.

The previous prime is 81348083. The next prime is 81348151. The reversal of 81348149 is 94184318.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35880100 + 45468049 = 5990^2 + 6743^2 .

It is a cyclic number.

It is not a de Polignac number, because 81348149 - 2²⁰ = 80299573 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81348049) 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, 210554 + ... + 210939.

It is an arithmetic number, because the mean of its divisors is an integer number (20442459).

Almost surely, 2^81348149 is an apocalyptic number.

It is an amenable number.

81348149 is a deficient number, since it is larger than the sum of its proper divisors (421687).

81348149 is a wasteful number, since it uses less digits than its factorization.

81348149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421686.

The product of its digits is 27648, while the sum is 38.

The square root of 81348149 is about 9019.3208724382. The cubic root of 81348149 is about 433.2938835224.

The spelling of 81348149 in words is "eighty-one million, three hundred forty-eight thousand, one hundred forty-nine".