561731 has 8 divisors (see below), whose sum is σ = 601344. Its totient is φ = 522880.

The previous prime is 561713. The next prime is 561733. The reversal of 561731 is 137165.

Added to its reverse (137165) it gives a square (698896 = 836²).

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 561731 - 2⁶ = 561667 is a prime.

It is a super-2 number, since 2×561731² = 631083432722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 561697 and 561706.

It is not an unprimeable number, because it can be changed into a prime (561733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2846 + ... + 3036.

It is an arithmetic number, because the mean of its divisors is an integer number (75168).

2⁵⁶¹⁷³¹ is an apocalyptic number.

561731 is a deficient number, since it is larger than the sum of its proper divisors (39613).

561731 is a wasteful number, since it uses less digits than its factorization.

561731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381.

The product of its digits is 630, while the sum is 23.

The square root of 561731 is about 749.4871579954. The cubic root of 561731 is about 82.5105465550.

Adding to 561731 its reverse (137165), we get a palindrome (698896).

The spelling of 561731 in words is "five hundred sixty-one thousand, seven hundred thirty-one".