81666803 has 8 divisors (see below), whose sum is σ = 85370880. Its totient is φ = 78029640.

The previous prime is 81666791. The next prime is 81666821. The reversal of 81666803 is 30866618.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81666803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81666853) 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, 14225 + ... + 19122.

It is an arithmetic number, because the mean of its divisors is an integer number (10671360).

Almost surely, 2^81666803 is an apocalyptic number.

81666803 is a deficient number, since it is larger than the sum of its proper divisors (3704077).

81666803 is a wasteful number, since it uses less digits than its factorization.

81666803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33457.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 81666803 is about 9036.9686842436. The cubic root of 81666803 is about 433.8589073947.

The spelling of 81666803 in words is "eighty-one million, six hundred sixty-six thousand, eight hundred three".