1218440 has 32 divisors (see below), whose sum is σ = 2782080. Its totient is φ = 480192.

The previous prime is 1218433. The next prime is 1218449. The reversal of 1218440 is 448121.

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

It is not an unprimeable number, because it can be changed into a prime (1218449) 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, 3137 + ... + 3503.

It is an arithmetic number, because the mean of its divisors is an integer number (86940).

2^1218440 is an apocalyptic number.

1218440 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 1218440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1391040).

1218440 is an abundant number, since it is smaller than the sum of its proper divisors (1563640).

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

1218440 is a wasteful number, since it uses less digits than its factorization.

1218440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461 (or 457 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 1218440 is about 1103.8296970095. The cubic root of 1218440 is about 106.8074096988.

The spelling of 1218440 in words is "one million, two hundred eighteen thousand, four hundred forty".