2201645 has 4 divisors (see below), whose sum is σ = 2641980. Its totient is φ = 1761312.

The previous prime is 2201627. The next prime is 2201669. The reversal of 2201645 is 5461022.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 611524 + 1590121 = 782^2 + 1261^2 .

It is a cyclic number.

It is not a de Polignac number, because 2201645 - 2⁶ = 2201581 is a prime.

It is a super-3 number, since 3×2201645³ = 32015709792649233375, which contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220160 + ... + 220169.

It is an arithmetic number, because the mean of its divisors is an integer number (660495).

2^2201645 is an apocalyptic number.

It is an amenable number.

2201645 is a deficient number, since it is larger than the sum of its proper divisors (440335).

2201645 is an equidigital number, since it uses as much as digits as its factorization.

2201645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440334.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 2201645 is about 1483.7941231856. The cubic root of 2201645 is about 130.0915528655.

Adding to 2201645 its reverse (5461022), we get a palindrome (7662667).

The spelling of 2201645 in words is "two million, two hundred one thousand, six hundred forty-five".