861011111 has 8 divisors (see below), whose sum is σ = 886452000. Its totient is φ = 835781760.

The previous prime is 861011077. The next prime is 861011119. The reversal of 861011111 is 111110168.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861011111 is a prime.

It is a Duffinian number.

861011111 is a modest number, since divided by 11111 gives 8610 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861011119) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44606 + ... + 60923.

It is an arithmetic number, because the mean of its divisors is an integer number (110806500).

Almost surely, 2^861011111 is an apocalyptic number.

861011111 is a deficient number, since it is larger than the sum of its proper divisors (25440889).

861011111 is a wasteful number, since it uses less digits than its factorization.

861011111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105769.

The product of its (nonzero) digits is 48, while the sum is 20.

The square root of 861011111 is about 29342.9908325651. The cubic root of 861011111 is about 951.3410832321.

Adding to 861011111 its reverse (111110168), we get a palindrome (972121279).

The spelling of 861011111 in words is "eight hundred sixty-one million, eleven thousand, one hundred eleven".