91771604109 has 6 divisors (see below), whose sum is σ = 132558983726. Its totient is φ = 61181069400.

The previous prime is 91771604107. The next prime is 91771604143. The reversal of 91771604109 is 90140617719.

91771604109 is a `hidden beast` number, since 9 + 1 + 77 + 160 + 410 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 74858601609 + 16913002500 = 273603^2 + 130050^2 .

It is not a de Polignac number, because 91771604109 - 2¹ = 91771604107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91771604107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5098422442 + ... + 5098422459.

Almost surely, 2^91771604109 is an apocalyptic number.

It is an amenable number.

91771604109 is a deficient number, since it is larger than the sum of its proper divisors (40787379617).

91771604109 is a wasteful number, since it uses less digits than its factorization.

91771604109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10196844907 (or 10196844904 counting only the distinct ones).

The product of its (nonzero) digits is 95256, while the sum is 45.

The spelling of 91771604109 in words is "ninety-one billion, seven hundred seventy-one million, six hundred four thousand, one hundred nine".