720191 has 4 divisors (see below), whose sum is σ = 728952. Its totient is φ = 711432.

The previous prime is 720179. The next prime is 720193. The reversal of 720191 is 191027.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 720191 - 2⁶ = 720127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 720191.

It is not an unprimeable number, because it can be changed into a prime (720193) 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, 4256 + ... + 4421.

It is an arithmetic number, because the mean of its divisors is an integer number (182238).

2⁷²⁰¹⁹¹ is an apocalyptic number.

720191 is a deficient number, since it is larger than the sum of its proper divisors (8761).

720191 is an equidigital number, since it uses as much as digits as its factorization.

720191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8760.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 720191 is about 848.6406777901. The cubic root of 720191 is about 89.6360196777.

The spelling of 720191 in words is "seven hundred twenty thousand, one hundred ninety-one".