720617 has 2 divisors, whose sum is σ = 720618. Its totient is φ = 720616.

The previous prime is 720611. The next prime is 720619. The reversal of 720617 is 716027.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 712336 + 8281 = 844^2 + 91^2 .

It is a cyclic number.

It is not a de Polignac number, because 720617 - 2⁸ = 720361 is a prime.

Together with 720619, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 720592 and 720601.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 720617.

It is not a weakly prime, because it can be changed into another prime (720611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360308 + 360309.

It is an arithmetic number, because the mean of its divisors is an integer number (360309).

2⁷²⁰⁶¹⁷ is an apocalyptic number.

It is an amenable number.

720617 is a deficient number, since it is larger than the sum of its proper divisors (1).

720617 is an equidigital number, since it uses as much as digits as its factorization.

720617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 720617 is about 848.8916303039. The cubic root of 720617 is about 89.6536897208.

The spelling of 720617 in words is "seven hundred twenty thousand, six hundred seventeen".