861117511 has 4 divisors (see below), whose sum is σ = 861249024. Its totient is φ = 860986000.

The previous prime is 861117479. The next prime is 861117529. The reversal of 861117511 is 115711168.

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 861117511 - 2⁵ = 861117479 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861117581) 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, 55390 + ... + 69211.

It is an arithmetic number, because the mean of its divisors is an integer number (215312256).

Almost surely, 2^861117511 is an apocalyptic number.

861117511 is a deficient number, since it is larger than the sum of its proper divisors (131513).

861117511 is a wasteful number, since it uses less digits than its factorization.

861117511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131512.

The product of its digits is 1680, while the sum is 31.

The square root of 861117511 is about 29344.8038160080. The cubic root of 861117511 is about 951.3802691461.

Adding to 861117511 its reverse (115711168), we get a palindrome (976828679).

The spelling of 861117511 in words is "eight hundred sixty-one million, one hundred seventeen thousand, five hundred eleven".