1181720 has 32 divisors (see below), whose sum is σ = 2747520. Its totient is φ = 456960.

The previous prime is 1181701. The next prime is 1181723. The reversal of 1181720 is 271811.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1181692 and 1181701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1181723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 764 + ... + 1716.

It is an arithmetic number, because the mean of its divisors is an integer number (85860).

2^1181720 is an apocalyptic number.

1181720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1181720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1373760).

1181720 is an abundant number, since it is smaller than the sum of its proper divisors (1565800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1181720 is a wasteful number, since it uses less digits than its factorization.

1181720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995 (or 991 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 1181720 is about 1087.0694550028. The cubic root of 1181720 is about 105.7234991448.

Subtracting from 1181720 its reverse (271811), we obtain a palindrome (909909).

The spelling of 1181720 in words is "one million, one hundred eighty-one thousand, seven hundred twenty".