2251805 has 4 divisors (see below), whose sum is σ = 2702172. Its totient is φ = 1801440.

The previous prime is 2251771. The next prime is 2251807. The reversal of 2251805 is 5081522.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5081522 = 2 ⋅2540761.

It can be written as a sum of positive squares in 2 ways, for example, as 241081 + 2010724 = 491^2 + 1418^2 .

It is not a de Polignac number, because 2251805 - 2⁶ = 2251741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2251807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225176 + ... + 225185.

It is an arithmetic number, because the mean of its divisors is an integer number (675543).

2^2251805 is an apocalyptic number.

It is an amenable number.

2251805 is a deficient number, since it is larger than the sum of its proper divisors (450367).

2251805 is an equidigital number, since it uses as much as digits as its factorization.

2251805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450366.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 2251805 is about 1500.6015460475. The cubic root of 2251805 is about 131.0721006277.

The spelling of 2251805 in words is "two million, two hundred fifty-one thousand, eight hundred five".