731240 has 32 divisors (see below), whose sum is σ = 1670760. Its totient is φ = 288000.

The previous prime is 731233. The next prime is 731243. The reversal of 731240 is 42137.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 556516 + 174724 = 746^2 + 418^2 .

It is not an unprimeable number, because it can be changed into a prime (731243) by changing a digit.

731240 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3950 + ... + 4130.

2⁷³¹²⁴⁰ is an apocalyptic number.

It is an amenable number.

731240 is an abundant number, since it is smaller than the sum of its proper divisors (939520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

731240 is a wasteful number, since it uses less digits than its factorization.

731240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 731240 is about 855.1257217509. The cubic root of 731240 is about 90.0920868158.

Adding to 731240 its reverse (42137), we get a palindrome (773377).

The spelling of 731240 in words is "seven hundred thirty-one thousand, two hundred forty".