91966721 has 8 divisors (see below), whose sum is σ = 114659904. Its totient is φ = 71662320.

The previous prime is 91966717. The next prime is 91966727. The reversal of 91966721 is 12766919.

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

It is a cyclic number.

It is not a de Polignac number, because 91966721 - 2² = 91966717 is a prime.

It is a super-3 number, since 3×91966721³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91966727) 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 7 ways as a sum of consecutive naturals, for example, 597110 + ... + 597263.

It is an arithmetic number, because the mean of its divisors is an integer number (14332488).

Almost surely, 2^91966721 is an apocalyptic number.

It is an amenable number.

91966721 is a deficient number, since it is larger than the sum of its proper divisors (22693183).

91966721 is a wasteful number, since it uses less digits than its factorization.

91966721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194391.

The product of its digits is 40824, while the sum is 41.

The square root of 91966721 is about 9589.9281019203. The cubic root of 91966721 is about 451.3813046274.

The spelling of 91966721 in words is "ninety-one million, nine hundred sixty-six thousand, seven hundred twenty-one".