2281981 has 8 divisors (see below), whose sum is σ = 2542680. Its totient is φ = 2033472.

The previous prime is 2281973. The next prime is 2281987. The reversal of 2281981 is 1891822.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4900 + 2277081 = 70^2 + 1509^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2281981 - 2³ = 2281973 is a prime.

It is a super-2 number, since 2×2281981² = 10414874568722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2281987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2650 + ... + 3403.

It is an arithmetic number, because the mean of its divisors is an integer number (317835).

2^2281981 is an apocalyptic number.

It is an amenable number.

2281981 is a deficient number, since it is larger than the sum of its proper divisors (260699).

2281981 is a wasteful number, since it uses less digits than its factorization.

2281981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6095.

The product of its digits is 2304, while the sum is 31.

The square root of 2281981 is about 1510.6227192784. The cubic root of 2281981 is about 131.6549951377.

It can be divided in two parts, 228 and 1981, that added together give a square (2209 = 47²).

The spelling of 2281981 in words is "two million, two hundred eighty-one thousand, nine hundred eighty-one".