91668205 has 4 divisors (see below), whose sum is σ = 110001852. Its totient is φ = 73334560.

The previous prime is 91668197. The next prime is 91668253. The reversal of 91668205 is 50286619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50286619 = 31 ⋅1622149.

It can be written as a sum of positive squares in 2 ways, for example, as 40717161 + 50951044 = 6381^2 + 7138^2 .

It is not a de Polignac number, because 91668205 - 2³ = 91668197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9166816 + ... + 9166825.

It is an arithmetic number, because the mean of its divisors is an integer number (27500463).

Almost surely, 2^91668205 is an apocalyptic number.

It is an amenable number.

91668205 is a deficient number, since it is larger than the sum of its proper divisors (18333647).

91668205 is a wasteful number, since it uses less digits than its factorization.

91668205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18333646.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 91668205 is about 9574.3514140646. The cubic root of 91668205 is about 450.8923937357.

It can be divided in two parts, 9166 and 8205, that added together give a palindrome (17371).

The spelling of 91668205 in words is "ninety-one million, six hundred sixty-eight thousand, two hundred five".