1188181 has 8 divisors (see below), whose sum is σ = 1292760. Its totient is φ = 1087488.

The previous prime is 1188179. The next prime is 1188197. The reversal of 1188181 is 1818811.

It can be written as a sum of positive squares in 4 ways, for example, as 562500 + 625681 = 750^2 + 791^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1188181 - 2¹ = 1188179 is a prime.

It is a super-2 number, since 2×1188181² = 2823548177522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1188151) 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, 316 + ... + 1573.

It is an arithmetic number, because the mean of its divisors is an integer number (161595).

2^1188181 is an apocalyptic number.

It is an amenable number.

1188181 is a deficient number, since it is larger than the sum of its proper divisors (104579).

1188181 is a wasteful number, since it uses less digits than its factorization.

1188181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1943.

The product of its digits is 512, while the sum is 28.

The square root of 1188181 is about 1090.0371553300. The cubic root of 1188181 is about 105.9158285160.

It can be divided in two parts, 11881 and 81, that multiplied together give a square (962361 = 981²).

The spelling of 1188181 in words is "one million, one hundred eighty-eight thousand, one hundred eighty-one".