1780123 has 6 divisors (see below), whose sum is σ = 1817844. Its totient is φ = 1742796.

The previous prime is 1780099. The next prime is 1780127. The reversal of 1780123 is 3210871.

It is a de Polignac number, because none of the positive numbers 2^k-1780123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1780094 and 1780103.

It is not an unprimeable number, because it can be changed into a prime (1780127) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10840 + ... + 11002.

It is an arithmetic number, because the mean of its divisors is an integer number (302974).

2^1780123 is an apocalyptic number.

1780123 is a deficient number, since it is larger than the sum of its proper divisors (37721).

1780123 is an frugal number, since it uses more digits than its factorization.

1780123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 1780123 is about 1334.2125018152. The cubic root of 1780123 is about 121.1946188435.

Adding to 1780123 its reverse (3210871), we get a palindrome (4990994).

The spelling of 1780123 in words is "one million, seven hundred eighty thousand, one hundred twenty-three".