91217666 has 8 divisors (see below), whose sum is σ = 138558720. Its totient is φ = 45031428.

The previous prime is 91217653. The next prime is 91217669. The reversal of 91217666 is 66671219.

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

It is a super-3 number, since 3×91217666³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (91217669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 288506 + ... + 288821.

It is an arithmetic number, because the mean of its divisors is an integer number (17319840).

Almost surely, 2^91217666 is an apocalyptic number.

91217666 is a deficient number, since it is larger than the sum of its proper divisors (47341054).

91217666 is a wasteful number, since it uses less digits than its factorization.

91217666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577408.

The product of its digits is 27216, while the sum is 38.

The square root of 91217666 is about 9550.7939984066. The cubic root of 91217666 is about 450.1524849493.

The spelling of 91217666 in words is "ninety-one million, two hundred seventeen thousand, six hundred sixty-six".