1780065 has 24 divisors (see below), whose sum is σ = 3526848. Its totient is φ = 813600.

The previous prime is 1780061. The next prime is 1780067. The reversal of 1780065 is 5600871.

It is not a de Polignac number, because 1780065 - 2² = 1780061 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1780061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2511 + ... + 3140.

It is an arithmetic number, because the mean of its divisors is an integer number (146952).

2^1780065 is an apocalyptic number.

1780065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1780065 is a deficient number, since it is larger than the sum of its proper divisors (1746783).

1780065 is a wasteful number, since it uses less digits than its factorization.

1780065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5669 (or 5666 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 1780065 is about 1334.1907659701. The cubic root of 1780065 is about 121.1933025741.

The spelling of 1780065 in words is "one million, seven hundred eighty thousand, sixty-five".