1780040 has 16 divisors (see below), whose sum is σ = 4005180. Its totient is φ = 712000.

The previous prime is 1780027. The next prime is 1780061. The reversal of 1780040 is 400871.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1779556 + 484 = 1334^2 + 22^2 .

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 = 1779994 and 1780021.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22211 + ... + 22290.

2^1780040 is an apocalyptic number.

1780040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1780040 is an abundant number, since it is smaller than the sum of its proper divisors (2225140).

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

1780040 is a wasteful number, since it uses less digits than its factorization.

1780040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44512 (or 44508 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 1780040 is about 1334.1813969622. The cubic root of 1780040 is about 121.1927352078.

The spelling of 1780040 in words is "one million, seven hundred eighty thousand, forty".