731281 has 4 divisors (see below), whose sum is σ = 738100. Its totient is φ = 724464.

The previous prime is 731267. The next prime is 731287. The reversal of 731281 is 182137.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 182137 = 23 ⋅7919.

It can be written as a sum of positive squares in 2 ways, for example, as 497025 + 234256 = 705^2 + 484^2 .

It is a cyclic number.

It is not a de Polignac number, because 731281 - 2⁵ = 731249 is a prime.

It is a super-2 number, since 2×731281² = 1069543801922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (731287) 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, 3246 + ... + 3463.

It is an arithmetic number, because the mean of its divisors is an integer number (184525).

2⁷³¹²⁸¹ is an apocalyptic number.

It is an amenable number.

731281 is a deficient number, since it is larger than the sum of its proper divisors (6819).

731281 is a wasteful number, since it uses less digits than its factorization.

731281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6818.

The product of its digits is 336, while the sum is 22.

The square root of 731281 is about 855.1496944980. The cubic root of 731281 is about 90.0937705797.

The spelling of 731281 in words is "seven hundred thirty-one thousand, two hundred eighty-one".