1780138 has 16 divisors (see below), whose sum is σ = 2898504. Its totient is φ = 816640.

The previous prime is 1780133. The next prime is 1780147. The reversal of 1780138 is 8310871.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1447209 + 332929 = 1203^2 + 577^2 .

It is not an unprimeable number, because it can be changed into a prime (1780133) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 756 + ... + 2032.

2^1780138 is an apocalyptic number.

1780138 is a deficient number, since it is larger than the sum of its proper divisors (1118366).

1780138 is a wasteful number, since it uses less digits than its factorization.

1780138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1337.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 1780138 is about 1334.2181230968. The cubic root of 1780138 is about 121.1949592533.

The spelling of 1780138 in words is "one million, seven hundred eighty thousand, one hundred thirty-eight".