720491 has 2 divisors, whose sum is σ = 720492. Its totient is φ = 720490.

The previous prime is 720481. The next prime is 720497. The reversal of 720491 is 194027.

It is a strong prime.

It is an emirp because it is prime and its reverse (194027) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-720491 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 720491.

It is not a weakly prime, because it can be changed into another prime (720497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360245 + 360246.

It is an arithmetic number, because the mean of its divisors is an integer number (360246).

2⁷²⁰⁴⁹¹ is an apocalyptic number.

720491 is a deficient number, since it is larger than the sum of its proper divisors (1).

720491 is an equidigital number, since it uses as much as digits as its factorization.

720491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 720491 is about 848.8174126395. The cubic root of 720491 is about 89.6484640954.

The spelling of 720491 in words is "seven hundred twenty thousand, four hundred ninety-one".