111721231 has 2 divisors, whose sum is σ = 111721232. Its totient is φ = 111721230.

The previous prime is 111721217. The next prime is 111721249. The reversal of 111721231 is 132127111.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 111721231 - 2⁵ = 111721199 is a prime.

It is a super-2 number, since 2×111721231² = 24963266912310722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 111721199 and 111721208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111721201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55860615 + 55860616.

It is an arithmetic number, because the mean of its divisors is an integer number (55860616).

Almost surely, 2^111721231 is an apocalyptic number.

111721231 is a deficient number, since it is larger than the sum of its proper divisors (1).

111721231 is an equidigital number, since it uses as much as digits as its factorization.

111721231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84, while the sum is 19.

The square root of 111721231 is about 10569.8264413376. The cubic root of 111721231 is about 481.6281961960.

Adding to 111721231 its reverse (132127111), we get a palindrome (243848342).

It can be divided in two parts, 11172 and 1231, that added together give a triangular number (12403 = T₁₅₇).

The spelling of 111721231 in words is "one hundred eleven million, seven hundred twenty-one thousand, two hundred thirty-one".