91771223 has 4 divisors (see below), whose sum is σ = 91798560. Its totient is φ = 91743888.

The previous prime is 91771217. The next prime is 91771241. The reversal of 91771223 is 32217719.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32217719 = 1031 ⋅31249.

It is a cyclic number.

It is not a de Polignac number, because 91771223 - 2¹² = 91767127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91771223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91371223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7790 + ... + 15627.

It is an arithmetic number, because the mean of its divisors is an integer number (22949640).

Almost surely, 2^91771223 is an apocalyptic number.

91771223 is a deficient number, since it is larger than the sum of its proper divisors (27337).

91771223 is a wasteful number, since it uses less digits than its factorization.

91771223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27336.

The product of its digits is 5292, while the sum is 32.

The square root of 91771223 is about 9579.7297978596. The cubic root of 91771223 is about 451.0612368770.

The spelling of 91771223 in words is "ninety-one million, seven hundred seventy-one thousand, two hundred twenty-three".