724781 has 2 divisors, whose sum is σ = 724782. Its totient is φ = 724780.

The previous prime is 724777. The next prime is 724783. The reversal of 724781 is 187427.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 697225 + 27556 = 835^2 + 166^2 .

It is a cyclic number.

It is not a de Polignac number, because 724781 - 2² = 724777 is a prime.

It is a super-2 number, since 2×724781² = 1050614995922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 724783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 724781.

It is not a weakly prime, because it can be changed into another prime (724783) 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 as a sum of consecutive naturals, namely, 362390 + 362391.

It is an arithmetic number, because the mean of its divisors is an integer number (362391).

2⁷²⁴⁷⁸¹ is an apocalyptic number.

It is an amenable number.

724781 is a deficient number, since it is larger than the sum of its proper divisors (1).

724781 is an equidigital number, since it uses as much as digits as its factorization.

724781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3136, while the sum is 29.

The square root of 724781 is about 851.3407073552. The cubic root of 724781 is about 89.8260425821.

The spelling of 724781 in words is "seven hundred twenty-four thousand, seven hundred eighty-one".