721713539 has 4 divisors (see below), whose sum is σ = 724811256. Its totient is φ = 718615824.

The previous prime is 721713533. The next prime is 721713541. The reversal of 721713539 is 935317127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 935317127 = 14423 ⋅64849.

It is a cyclic number.

It is not a de Polignac number, because 721713539 - 2¹⁶ = 721648003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721713533) 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, 1548509 + ... + 1548974.

It is an arithmetic number, because the mean of its divisors is an integer number (181202814).

Almost surely, 2^721713539 is an apocalyptic number.

721713539 is a deficient number, since it is larger than the sum of its proper divisors (3097717).

721713539 is a wasteful number, since it uses less digits than its factorization.

721713539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3097716.

The product of its digits is 39690, while the sum is 38.

The square root of 721713539 is about 26864.7266689985. The cubic root of 721713539 is about 896.9914102384.

The spelling of 721713539 in words is "seven hundred twenty-one million, seven hundred thirteen thousand, five hundred thirty-nine".