721197287 has 2 divisors, whose sum is σ = 721197288. Its totient is φ = 721197286.

The previous prime is 721197271. The next prime is 721197289. The reversal of 721197287 is 782791127.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 721197287 - 2⁴ = 721197271 is a prime.

Together with 721197289, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721197289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360598643 + 360598644.

It is an arithmetic number, because the mean of its divisors is an integer number (360598644).

Almost surely, 2^721197287 is an apocalyptic number.

721197287 is a deficient number, since it is larger than the sum of its proper divisors (1).

721197287 is an equidigital number, since it uses as much as digits as its factorization.

721197287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98784, while the sum is 44.

The square root of 721197287 is about 26855.1165888365. The cubic root of 721197287 is about 896.7774823003. Note that the first 3 decimals are identical.

The spelling of 721197287 in words is "seven hundred twenty-one million, one hundred ninety-seven thousand, two hundred eighty-seven".