2263781 has 4 divisors (see below), whose sum is σ = 2437932. Its totient is φ = 2089632.

The previous prime is 2263777. The next prime is 2263787. The reversal of 2263781 is 1873622.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1873622 = 2 ⋅936811.

It can be written as a sum of positive squares in 2 ways, for example, as 586756 + 1677025 = 766^2 + 1295^2 .

It is a cyclic number.

It is not a de Polignac number, because 2263781 - 2² = 2263777 is a prime.

It is a super-2 number, since 2×2263781² = 10249408831922, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2⁷ + 2²¹ + 6⁶ + 3⁷ + 7⁶ + 8 + 1 .

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2263787) 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, 87056 + ... + 87081.

It is an arithmetic number, because the mean of its divisors is an integer number (609483).

2^2263781 is an apocalyptic number.

It is an amenable number.

2263781 is a deficient number, since it is larger than the sum of its proper divisors (174151).

2263781 is a wasteful number, since it uses less digits than its factorization.

2263781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174150.

The product of its digits is 4032, while the sum is 29.

The square root of 2263781 is about 1504.5866542011. The cubic root of 2263781 is about 131.3040545301.

The spelling of 2263781 in words is "two million, two hundred sixty-three thousand, seven hundred eighty-one".