724861 has 4 divisors (see below), whose sum is σ = 729472. Its totient is φ = 720252.

The previous prime is 724853. The next prime is 724879. The reversal of 724861 is 168427.

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: 168427 = 7 ⋅24061.

It is a cyclic number.

It is not a de Polignac number, because 724861 - 2³ = 724853 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (724961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2061 + ... + 2386.

It is an arithmetic number, because the mean of its divisors is an integer number (182368).

2⁷²⁴⁸⁶¹ is an apocalyptic number.

It is an amenable number.

724861 is a deficient number, since it is larger than the sum of its proper divisors (4611).

724861 is a wasteful number, since it uses less digits than its factorization.

724861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4610.

The product of its digits is 2688, while the sum is 28.

The square root of 724861 is about 851.3876907731. The cubic root of 724861 is about 89.8293474052.

The spelling of 724861 in words is "seven hundred twenty-four thousand, eight hundred sixty-one".