726584021 has 8 divisors (see below), whose sum is σ = 732596184. Its totient is φ = 720582400.

The previous prime is 726584017. The next prime is 726584041. The reversal of 726584021 is 120485627.

It can be written as a sum of positive squares in 4 ways, for example, as 209931121 + 516652900 = 14489^2 + 22730^2 .

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 726584021 - 2² = 726584017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726584041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194471 + ... + 198171.

It is an arithmetic number, because the mean of its divisors is an integer number (91574523).

Almost surely, 2^726584021 is an apocalyptic number.

It is an amenable number.

726584021 is a deficient number, since it is larger than the sum of its proper divisors (6012163).

726584021 is a wasteful number, since it uses less digits than its factorization.

726584021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5271.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 726584021 is about 26955.2225180947. Note that the first 3 decimals coincide. The cubic root of 726584021 is about 899.0046696062.

The spelling of 726584021 in words is "seven hundred twenty-six million, five hundred eighty-four thousand, twenty-one".