81866298 has 8 divisors (see below), whose sum is σ = 163732608. Its totient is φ = 27288764.

The previous prime is 81866297. The next prime is 81866321. The reversal of 81866298 is 89266818.

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

81866298 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81866297) 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, 6822186 + ... + 6822197.

It is an arithmetic number, because the mean of its divisors is an integer number (20466576).

Almost surely, 2^81866298 is an apocalyptic number.

81866298 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81866298 is a wasteful number, since it uses less digits than its factorization.

81866298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13644388.

The product of its digits is 331776, while the sum is 48.

The square root of 81866298 is about 9047.9996684350. Note that the first 3 decimals coincide. The cubic root of 81866298 is about 434.2118957911.

The spelling of 81866298 in words is "eighty-one million, eight hundred sixty-six thousand, two hundred ninety-eight".