731609 has 4 divisors (see below), whose sum is σ = 738816. Its totient is φ = 724404.

The previous prime is 731603. The next prime is 731611. The reversal of 731609 is 906137.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 906137 = 233 ⋅3889.

It is a cyclic number.

It is not a de Polignac number, because 731609 - 2⁴ = 731593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (731603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3449 + ... + 3654.

It is an arithmetic number, because the mean of its divisors is an integer number (184704).

2⁷³¹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

731609 is a deficient number, since it is larger than the sum of its proper divisors (7207).

731609 is a wasteful number, since it uses less digits than its factorization.

731609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7206.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 731609 is about 855.3414522867. The cubic root of 731609 is about 90.1072384257.

The spelling of 731609 in words is "seven hundred thirty-one thousand, six hundred nine".