1801565 has 16 divisors (see below), whose sum is σ = 2280960. Its totient is φ = 1364160.

The previous prime is 1801549. The next prime is 1801577. The reversal of 1801565 is 5651081.

It is not a de Polignac number, because 1801565 - 2⁴ = 1801549 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9047 + ... + 9243.

It is an arithmetic number, because the mean of its divisors is an integer number (142560).

2^1801565 is an apocalyptic number.

It is an amenable number.

1801565 is a deficient number, since it is larger than the sum of its proper divisors (479395).

1801565 is a wasteful number, since it uses less digits than its factorization.

1801565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292.

The product of its (nonzero) digits is 1200, while the sum is 26.

The square root of 1801565 is about 1342.2239008452. The cubic root of 1801565 is about 121.6792839441.

The spelling of 1801565 in words is "one million, eight hundred one thousand, five hundred sixty-five".