1801645 has 8 divisors (see below), whose sum is σ = 2169720. Its totient is φ = 1436160.

The previous prime is 1801619. The next prime is 1801669. The reversal of 1801645 is 5461081.

It can be written as a sum of positive squares in 4 ways, for example, as 259081 + 1542564 = 509^2 + 1242^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1801645 - 2⁷ = 1801517 is a prime.

It is a super-3 number, since 3×1801645³ = 17544012050959233375, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1605 + ... + 2485.

It is an arithmetic number, because the mean of its divisors is an integer number (271215).

2^1801645 is an apocalyptic number.

It is an amenable number.

1801645 is a deficient number, since it is larger than the sum of its proper divisors (368075).

1801645 is an equidigital number, since it uses as much as digits as its factorization.

1801645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1295.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1801645 is about 1342.2537018016. The cubic root of 1801645 is about 121.6810850075.

The spelling of 1801645 in words is "one million, eight hundred one thousand, six hundred forty-five".