721713553 has 4 divisors (see below), whose sum is σ = 787323888. Its totient is φ = 656103220.

The previous prime is 721713541. The next prime is 721713569. The reversal of 721713553 is 355317127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 721713553 - 2⁵ = 721713521 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, 32805151 + ... + 32805172.

It is an arithmetic number, because the mean of its divisors is an integer number (196830972).

Almost surely, 2^721713553 is an apocalyptic number.

It is an amenable number.

721713553 is a deficient number, since it is larger than the sum of its proper divisors (65610335).

721713553 is a wasteful number, since it uses less digits than its factorization.

721713553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65610334.

The product of its digits is 22050, while the sum is 34.

The square root of 721713553 is about 26864.7269295632. The cubic root of 721713553 is about 896.9914160384.

The spelling of 721713553 in words is "seven hundred twenty-one million, seven hundred thirteen thousand, five hundred fifty-three".