81249 has 16 divisors (see below), whose sum is σ = 127872. Its totient is φ = 44928.

The previous prime is 81239. The next prime is 81281. The reversal of 81249 is 94218.

It is a trimorphic number since its cube, 536357148681249, ends in 81249.

It is not a de Polignac number, because 81249 - 2⁴ = 81233 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1077 + ... + 1149.

It is an arithmetic number, because the mean of its divisors is an integer number (7992).

2⁸¹²⁴⁹ is an apocalyptic number.

It is an amenable number.

81249 is a deficient number, since it is larger than the sum of its proper divisors (46623).

81249 is a wasteful number, since it uses less digits than its factorization.

81249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136.

The product of its digits is 576, while the sum is 24.

The square root of 81249 is about 285.0421021533. The cubic root of 81249 is about 43.3117775762.

Subtracting from 81249 its sum of digits (24), we obtain a square (81225 = 285²).

It can be divided in two parts, 812 and 49, that added together give a triangular number (861 = T₄₁).

The spelling of 81249 in words is "eighty-one thousand, two hundred forty-nine".