91777 has 6 divisors (see below), whose sum is σ = 106818. Its totient is φ = 78624.

The previous prime is 91771. The next prime is 91781. The reversal of 91777 is 77719.

It can be written as a sum of positive squares in only one way, i.e., 53361 + 38416 = 231^2 + 196^2 .

It is not a de Polignac number, because 91777 - 2¹⁵ = 59009 is a prime.

It is a Duffinian number.

91777 is a modest number, since divided by 777 gives 91 as remainder.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (91771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 888 + ... + 985.

It is an arithmetic number, because the mean of its divisors is an integer number (17803).

2⁹¹⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

91777 is a deficient number, since it is larger than the sum of its proper divisors (15041).

91777 is a wasteful number, since it uses less digits than its factorization.

91777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1887 (or 1880 counting only the distinct ones).

The product of its digits is 3087, while the sum is 31.

The square root of 91777 is about 302.9471901174. The cubic root of 91777 is about 45.1070701449.

Adding to 91777 its product of digits (3087), we get a square (94864 = 308²).

It can be divided in two parts, 91 and 777, that multiplied together give a palindrome (70707).

The spelling of 91777 in words is "ninety-one thousand, seven hundred seventy-seven".