681731111 has 4 divisors (see below), whose sum is σ = 681797424. Its totient is φ = 681664800.

The previous prime is 681731087. The next prime is 681731119. The reversal of 681731111 is 111137186.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 681731111 - 2²² = 677536807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681731119) 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, 14075 + ... + 39516.

It is an arithmetic number, because the mean of its divisors is an integer number (170449356).

Almost surely, 2^681731111 is an apocalyptic number.

681731111 is a deficient number, since it is larger than the sum of its proper divisors (66313).

681731111 is a wasteful number, since it uses less digits than its factorization.

681731111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66312.

The product of its digits is 1008, while the sum is 29.

The square root of 681731111 is about 26109.9810608893. The cubic root of 681731111 is about 880.1115178060. Note that the first 3 decimals are identical.

Adding to 681731111 its reverse (111137186), we get a palindrome (792868297).

The spelling of 681731111 in words is "six hundred eighty-one million, seven hundred thirty-one thousand, one hundred eleven".