81534249 has 8 divisors (see below), whose sum is σ = 120791520. Its totient is φ = 54356148.

The previous prime is 81534239. The next prime is 81534251. The reversal of 81534249 is 94243518.

81534249 is a `hidden beast` number, since 81 + 534 + 2 + 49 = 666.

It is not a de Polignac number, because 81534249 - 2⁷ = 81534121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81534209) 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 7 ways as a sum of consecutive naturals, for example, 1509867 + ... + 1509920.

It is an arithmetic number, because the mean of its divisors is an integer number (15098940).

Almost surely, 2^81534249 is an apocalyptic number.

It is an amenable number.

81534249 is a deficient number, since it is larger than the sum of its proper divisors (39257271).

81534249 is a wasteful number, since it uses less digits than its factorization.

81534249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3019796 (or 3019790 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81534249 is about 9029.6317200648. The cubic root of 81534249 is about 433.6240470663.

The spelling of 81534249 in words is "eighty-one million, five hundred thirty-four thousand, two hundred forty-nine".