191617 has 4 divisors (see below), whose sum is σ = 193860. Its totient is φ = 189376.

The previous prime is 191599. The next prime is 191621. The reversal of 191617 is 716191.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24336 + 167281 = 156^2 + 409^2 .

It is a cyclic number.

It is not a de Polignac number, because 191617 - 2¹⁵ = 158849 is a prime.

It is a Duffinian number.

191617 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 191591 and 191600.

It is not an unprimeable number, because it can be changed into a prime (191627) 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, 988 + ... + 1165.

It is an arithmetic number, because the mean of its divisors is an integer number (48465).

2¹⁹¹⁶¹⁷ is an apocalyptic number.

It is an amenable number.

191617 is a deficient number, since it is larger than the sum of its proper divisors (2243).

191617 is an equidigital number, since it uses as much as digits as its factorization.

191617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2242.

The product of its digits is 378, while the sum is 25.

The square root of 191617 is about 437.7407908797. The cubic root of 191617 is about 57.6515974450.

It can be divided in two parts, 191 and 617, that added together give a palindrome (808).

The spelling of 191617 in words is "one hundred ninety-one thousand, six hundred seventeen".