7281981 has 28 divisors (see below), whose sum is σ = 12486432. Its totient is φ = 4158216.

The previous prime is 7281977. The next prime is 7282003. The reversal of 7281981 is 1891827.

It is not a de Polignac number, because 7281981 - 2² = 7281977 is a prime.

It is a super-2 number, since 2×7281981² = 106054494568722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7281941) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 4390 + ... + 5816.

It is an arithmetic number, because the mean of its divisors is an integer number (445944).

Almost surely, 2^7281981 is an apocalyptic number.

It is an amenable number.

7281981 is a deficient number, since it is larger than the sum of its proper divisors (5204451).

7281981 is an equidigital number, since it uses as much as digits as its factorization.

7281981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1452 (or 1437 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 7281981 is about 2698.5145914002. The cubic root of 7281981 is about 193.8279996735.

It can be divided in two parts, 72819 and 81, that added together give a square (72900 = 270²).

The spelling of 7281981 in words is "seven million, two hundred eighty-one thousand, nine hundred eighty-one".