724717681 has 4 divisors (see below), whose sum is σ = 742393764. Its totient is φ = 707041600.

The previous prime is 724717663. The next prime is 724717699. The reversal of 724717681 is 186717427.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (724717663) and next prime (724717699).

It can be written as a sum of positive squares in 2 ways, for example, as 87609600 + 637108081 = 9360^2 + 25241^2 .

It is a cyclic number.

It is not a de Polignac number, because 724717681 - 2¹⁵ = 724684913 is a prime.

It is a super-2 number, since 2×724717681² = 1050431434308035522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (724717621) 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, 8837980 + ... + 8838061.

It is an arithmetic number, because the mean of its divisors is an integer number (185598441).

Almost surely, 2^724717681 is an apocalyptic number.

It is an amenable number.

724717681 is a deficient number, since it is larger than the sum of its proper divisors (17676083).

724717681 is a wasteful number, since it uses less digits than its factorization.

724717681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17676082.

The product of its digits is 131712, while the sum is 43.

The square root of 724717681 is about 26920.5809929875. The cubic root of 724717681 is about 898.2342668348.

The spelling of 724717681 in words is "seven hundred twenty-four million, seven hundred seventeen thousand, six hundred eighty-one".