720517 has 4 divisors (see below), whose sum is σ = 823456. Its totient is φ = 617580.

The previous prime is 720497. The next prime is 720527. The reversal of 720517 is 715027.

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, and also an emirpimes, since its reverse is a distinct semiprime: 715027 = 19 ⋅37633.

It is a cyclic number.

It is not a de Polignac number, because 720517 - 2¹⁵ = 687749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51459 + ... + 51472.

It is an arithmetic number, because the mean of its divisors is an integer number (205864).

2⁷²⁰⁵¹⁷ is an apocalyptic number.

It is an amenable number.

720517 is a deficient number, since it is larger than the sum of its proper divisors (102939).

720517 is a wasteful number, since it uses less digits than its factorization.

720517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102938.

The product of its (nonzero) digits is 490, while the sum is 22.

The square root of 720517 is about 848.8327279270. The cubic root of 720517 is about 89.6495424490.

Subtracting from 720517 its product of nonzero digits (490), we obtain a palindrome (720027).

The spelling of 720517 in words is "seven hundred twenty thousand, five hundred seventeen".