81049249 has 4 divisors (see below), whose sum is σ = 81078340. Its totient is φ = 81020160.

The previous prime is 81049247. The next prime is 81049253. The reversal of 81049249 is 94294018.

It is a happy number.

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 3873024 + 77176225 = 1968^2 + 8785^2 .

It is a cyclic number.

It is not a de Polignac number, because 81049249 - 2¹ = 81049247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81049247) 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, 9864 + ... + 16105.

It is an arithmetic number, because the mean of its divisors is an integer number (20269585).

Almost surely, 2^81049249 is an apocalyptic number.

It is an amenable number.

81049249 is a deficient number, since it is larger than the sum of its proper divisors (29091).

81049249 is a wasteful number, since it uses less digits than its factorization.

81049249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29090.

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

The square root of 81049249 is about 9002.7356397931. The cubic root of 81049249 is about 432.7625438803.

The spelling of 81049249 in words is "eighty-one million, forty-nine thousand, two hundred forty-nine".