721117 has 2 divisors, whose sum is σ = 721118. Its totient is φ = 721116.

The previous prime is 721111. The next prime is 721129. The reversal of 721117 is 711127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 622521 + 98596 = 789^2 + 314^2 .

It is a cyclic number.

It is not a de Polignac number, because 721117 - 2³ = 721109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 721094 and 721103.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360558 + 360559.

It is an arithmetic number, because the mean of its divisors is an integer number (360559).

2⁷²¹¹¹⁷ is an apocalyptic number.

It is an amenable number.

721117 is a deficient number, since it is larger than the sum of its proper divisors (1).

721117 is an equidigital number, since it uses as much as digits as its factorization.

721117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 98, while the sum is 19.

The square root of 721117 is about 849.1860809034. The cubic root of 721117 is about 89.6744203267.

It can be divided in two parts, 721 and 117, that added together give a palindrome (838).

The spelling of 721117 in words is "seven hundred twenty-one thousand, one hundred seventeen", and thus it is an iban number.