81666098 has 8 divisors (see below), whose sum is σ = 122564208. Its totient is φ = 40811364.

The previous prime is 81666071. The next prime is 81666131. The reversal of 81666098 is 89066618.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5636 + ... + 13967.

It is an arithmetic number, because the mean of its divisors is an integer number (15320526).

Almost surely, 2^81666098 is an apocalyptic number.

81666098 is a deficient number, since it is larger than the sum of its proper divisors (40898110).

81666098 is a wasteful number, since it uses less digits than its factorization.

81666098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21688.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 81666098 is about 9036.9296777169. The cubic root of 81666098 is about 433.8576589421.

The spelling of 81666098 in words is "eighty-one million, six hundred sixty-six thousand, ninety-eight".