81449 has 4 divisors (see below), whose sum is σ = 82560. Its totient is φ = 80340.

The previous prime is 81439. The next prime is 81457. The reversal of 81449 is 94418.

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 81449 - 2¹⁶ = 15913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81409) 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, 437 + ... + 594.

It is an arithmetic number, because the mean of its divisors is an integer number (20640).

2⁸¹⁴⁴⁹ is an apocalyptic number.

It is an amenable number.

81449 is a deficient number, since it is larger than the sum of its proper divisors (1111).

81449 is a wasteful number, since it uses less digits than its factorization.

81449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110.

The product of its digits is 1152, while the sum is 26.

The square root of 81449 is about 285.3927118901. The cubic root of 81449 is about 43.3472867622.

The spelling of 81449 in words is "eighty-one thousand, four hundred forty-nine".