Search a number
-
+
111981 = 3163229
BaseRepresentation
bin11011010101101101
312200121110
4123111231
512040411
62222233
7644322
oct332555
9180543
10111981
1177151
1254979
133bc7c
142cb49
15232a6
hex1b56d

111981 has 8 divisors (see below), whose sum is σ = 150880. Its totient is φ = 73872.

The previous prime is 111977. The next prime is 111997. The reversal of 111981 is 189111.

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

It is not a de Polignac number, because 111981 - 22 = 111977 is a prime.

It is a super-2 number, since 2×1119812 = 25079488722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

111981 is a lucky number.

It is a plaindrome in base 6.

It is a nialpdrome in base 7.

It is a zygodrome in base 6.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 375 + ... + 603.

It is an arithmetic number, because the mean of its divisors is an integer number (18860).

2111981 is an apocalyptic number.

It is an amenable number.

111981 is a deficient number, since it is larger than the sum of its proper divisors (38899).

111981 is a wasteful number, since it uses less digits than its factorization.

111981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395.

The product of its digits is 72, while the sum is 21.

The square root of 111981 is about 334.6356227302. The cubic root of 111981 is about 48.2001193732.

The spelling of 111981 in words is "one hundred eleven thousand, nine hundred eighty-one".

Divisors: 1 3 163 229 489 687 37327 111981