1211440 has 40 divisors (see below), whose sum is σ = 2968560. Its totient is φ = 458496.

The previous prime is 1211423. The next prime is 1211443. The reversal of 1211440 is 441121.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×1211440³ = 5333680326461952000, which contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1211440.

It is not an unprimeable number, because it can be changed into a prime (1211443) 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, 1122 + ... + 1918.

It is an arithmetic number, because the mean of its divisors is an integer number (74214).

2^1211440 is an apocalyptic number.

1211440 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 1211440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1484280).

1211440 is an abundant number, since it is smaller than the sum of its proper divisors (1757120).

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

1211440 is a wasteful number, since it uses less digits than its factorization.

1211440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1211440 is about 1100.6543508295. The cubic root of 1211440 is about 106.6024787430.

Adding to 1211440 its reverse (441121), we get a palindrome (1652561).

The spelling of 1211440 in words is "one million, two hundred eleven thousand, four hundred forty".