1812240 has 80 divisors (see below), whose sum is σ = 6249600. Its totient is φ = 482688.

The previous prime is 1812233. The next prime is 1812263. The reversal of 1812240 is 422181.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1741 + ... + 2579.

It is an arithmetic number, because the mean of its divisors is an integer number (78120).

2^1812240 is an apocalyptic number.

1812240 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 1812240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3124800).

1812240 is an abundant number, since it is smaller than the sum of its proper divisors (4437360).

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

1812240 is a wasteful number, since it uses less digits than its factorization.

1812240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861 (or 849 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1812240 is about 1346.1946367446. The cubic root of 1812240 is about 121.9191437723.

The spelling of 1812240 in words is "one million, eight hundred twelve thousand, two hundred forty".