91691216 has 10 divisors (see below), whose sum is σ = 177651762. Its totient is φ = 45845600.

The previous prime is 91691213. The next prime is 91691221. The reversal of 91691216 is 61219619.

It can be written as a sum of positive squares in only one way, i.e., 60777616 + 30913600 = 7796^2 + 5560^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91691213) 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 as a sum of consecutive naturals, namely, 2865335 + ... + 2865366.

Almost surely, 2^91691216 is an apocalyptic number.

It is an amenable number.

91691216 is a deficient number, since it is larger than the sum of its proper divisors (85960546).

91691216 is a wasteful number, since it uses less digits than its factorization.

91691216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5730709 (or 5730703 counting only the distinct ones).

The product of its digits is 5832, while the sum is 35.

The square root of 91691216 is about 9575.5530388589. The cubic root of 91691216 is about 450.9301189820.

The spelling of 91691216 in words is "ninety-one million, six hundred ninety-one thousand, two hundred sixteen".