724561 has 4 divisors (see below), whose sum is σ = 730224. Its totient is φ = 718900.

The previous prime is 724553. The next prime is 724567. The reversal of 724561 is 165427.

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.

It is a cyclic number.

It is not a de Polignac number, because 724561 - 2³ = 724553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (724567) 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, 2635 + ... + 2896.

It is an arithmetic number, because the mean of its divisors is an integer number (182556).

2⁷²⁴⁵⁶¹ is an apocalyptic number.

It is an amenable number.

724561 is a deficient number, since it is larger than the sum of its proper divisors (5663).

724561 is a wasteful number, since it uses less digits than its factorization.

724561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5662.

The product of its digits is 1680, while the sum is 25.

The square root of 724561 is about 851.2114895841. The cubic root of 724561 is about 89.8169530644.

Adding to 724561 its reverse (165427), we get a palindrome (889988).

The spelling of 724561 in words is "seven hundred twenty-four thousand, five hundred sixty-one".