1918440 has 72 divisors (see below), whose sum is σ = 6321510. Its totient is φ = 504576.

The previous prime is 1918439. The next prime is 1918451. The reversal of 1918440 is 448191.

It can be written as a sum of positive squares in 3 ways, for example, as 1633284 + 285156 = 1278^2 + 534^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 26244 + ... + 26316.

2^1918440 is an apocalyptic number.

1918440 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 1918440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3160755).

1918440 is an abundant number, since it is smaller than the sum of its proper divisors (4403070).

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

1918440 is a wasteful number, since it uses less digits than its factorization.

1918440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1918440 is about 1385.0776151538. The cubic root of 1918440 is about 124.2556294318.

The spelling of 1918440 in words is "one million, nine hundred eighteen thousand, four hundred forty".