1780420 has 12 divisors (see below), whose sum is σ = 3738924. Its totient is φ = 712160.

The previous prime is 1780411. The next prime is 1780439. The reversal of 1780420 is 240871.

It can be written as a sum of positive squares in 2 ways, for example, as 948676 + 831744 = 974^2 + 912^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1780391 and 1780400.

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, 44491 + ... + 44530.

It is an arithmetic number, because the mean of its divisors is an integer number (311577).

2^1780420 is an apocalyptic number.

1780420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1780420 is an abundant number, since it is smaller than the sum of its proper divisors (1958504).

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

1780420 is a wasteful number, since it uses less digits than its factorization.

1780420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89030 (or 89028 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 1780420 is about 1334.3237987835. The cubic root of 1780420 is about 121.2013586025.

The spelling of 1780420 in words is "one million, seven hundred eighty thousand, four hundred twenty".