721365541 has 8 divisors (see below), whose sum is σ = 793384704. Its totient is φ = 651707760.

The previous prime is 721365509. The next prime is 721365551. The reversal of 721365541 is 145563127.

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 721365541 - 2⁵ = 721365509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721365497 and 721365506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721365551) 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, 589705 + ... + 590926.

It is an arithmetic number, because the mean of its divisors is an integer number (99173088).

Almost surely, 2^721365541 is an apocalyptic number.

It is an amenable number.

721365541 is a deficient number, since it is larger than the sum of its proper divisors (72019163).

721365541 is a wasteful number, since it uses less digits than its factorization.

721365541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180691.

The product of its digits is 25200, while the sum is 34.

The square root of 721365541 is about 26858.2490307913. The cubic root of 721365541 is about 896.8472157232.

It can be divided in two parts, 72136 and 5541, that added together give a palindrome (77677).

The spelling of 721365541 in words is "seven hundred twenty-one million, three hundred sixty-five thousand, five hundred forty-one".