81802249 has 8 divisors (see below), whose sum is σ = 87425568. Its totient is φ = 76269120.

The previous prime is 81802241. The next prime is 81802271. The reversal of 81802249 is 94220818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81802249 - 2³ = 81802241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81802241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20667 + ... + 24304.

It is an arithmetic number, because the mean of its divisors is an integer number (10928196).

Almost surely, 2^81802249 is an apocalyptic number.

It is an amenable number.

81802249 is a deficient number, since it is larger than the sum of its proper divisors (5623319).

81802249 is a wasteful number, since it uses less digits than its factorization.

81802249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45095.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 81802249 is about 9044.4595747894. The cubic root of 81802249 is about 434.0986294278.

The spelling of 81802249 in words is "eighty-one million, eight hundred two thousand, two hundred forty-nine".