81665614 has 8 divisors (see below), whose sum is σ = 122792040. Its totient is φ = 40734936.

The previous prime is 81665581. The next prime is 81665657. The reversal of 81665614 is 41656618.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47889 + ... + 49564.

It is an arithmetic number, because the mean of its divisors is an integer number (15349005).

Almost surely, 2^81665614 is an apocalyptic number.

81665614 is a deficient number, since it is larger than the sum of its proper divisors (41126426).

81665614 is a wasteful number, since it uses less digits than its factorization.

81665614 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97874.

The product of its digits is 34560, while the sum is 37.

The square root of 81665614 is about 9036.9028986705. The cubic root of 81665614 is about 433.8568018442.

It can be divided in two parts, 816 and 65614, that added together give a triangular number (66430 = T₃₆₄).

The spelling of 81665614 in words is "eighty-one million, six hundred sixty-five thousand, six hundred fourteen".