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111221 = 1110111

111221 has 4 divisors (see below), whose sum is σ = 121344. Its totient is φ = 101100.

The previous prime is 111217. The next prime is 111227. The reversal of 111221 is 122111.

Adding to 111221 its reverse (122111), we get a palindrome (233332).

It can be divided in two parts, 111 and 221, that multiplied together give a triangular number (24531 = T221).

111221 is nontrivially palindromic in base 12.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 111221 - 22 = 111217 is a prime.

It is a super-2 number, since 2×1112212 = 24740221682, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 111199 and 111208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111227) 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, 5045 + ... + 5066.

It is an arithmetic number, because the mean of its divisors is an integer number (30336).

2111221 is an apocalyptic number.

111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111221 is a deficient number, since it is larger than the sum of its proper divisors (10123).

111221 is a wasteful number, since it uses less digits than its factorization.

111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10122.

The product of its digits is 4, while the sum is 8.

The square root of 111221 is about 333.4981259318. The cubic root of 111221 is about 48.0908291753.

The spelling of 111221 in words is "one hundred eleven thousand, two hundred twenty-one", and thus it is an iban number.

Divisors: 1 11 10111 111221