91688121 has 12 divisors (see below), whose sum is σ = 151358272. Its totient is φ = 52393176.

The previous prime is 91688119. The next prime is 91688147. The reversal of 91688121 is 12188619.

It is not a de Polignac number, because 91688121 - 2¹ = 91688119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91688101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 727621 + ... + 727746.

Almost surely, 2^91688121 is an apocalyptic number.

It is an amenable number.

91688121 is a deficient number, since it is larger than the sum of its proper divisors (59670151).

91688121 is a wasteful number, since it uses less digits than its factorization.

91688121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1455380 (or 1455377 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 91688121 is about 9575.3914280305. The cubic root of 91688121 is about 450.9250452701.

It can be divided in two parts, 91688 and 121, that added together give a square (91809 = 303²).

The spelling of 91688121 in words is "ninety-one million, six hundred eighty-eight thousand, one hundred twenty-one".