861611 has 4 divisors (see below), whose sum is σ = 912312. Its totient is φ = 810912.

The previous prime is 861599. The next prime is 861613. The reversal of 861611 is 116168.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 861611 - 2⁶ = 861547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25325 + ... + 25358.

It is an arithmetic number, because the mean of its divisors is an integer number (228078).

2⁸⁶¹⁶¹¹ is an apocalyptic number.

861611 is a deficient number, since it is larger than the sum of its proper divisors (50701).

861611 is a wasteful number, since it uses less digits than its factorization.

861611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50700.

The product of its digits is 288, while the sum is 23.

The square root of 861611 is about 928.2300361441. The cubic root of 861611 is about 95.1561973360.

Adding to 861611 its reverse (116168), we get a palindrome (977779).

The spelling of 861611 in words is "eight hundred sixty-one thousand, six hundred eleven".