721163501 has 2 divisors, whose sum is σ = 721163502. Its totient is φ = 721163500.

The previous prime is 721163497. The next prime is 721163557. The reversal of 721163501 is 105361127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 451350025 + 269813476 = 21245^2 + 16426^2 .

It is an emirp because it is prime and its reverse (105361127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721163501 - 2² = 721163497 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721163591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360581750 + 360581751.

It is an arithmetic number, because the mean of its divisors is an integer number (360581751).

Almost surely, 2^721163501 is an apocalyptic number.

It is an amenable number.

721163501 is a deficient number, since it is larger than the sum of its proper divisors (1).

721163501 is an equidigital number, since it uses as much as digits as its factorization.

721163501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 721163501 is about 26854.4875393294. The cubic root of 721163501 is about 896.7634782741.

The spelling of 721163501 in words is "seven hundred twenty-one million, one hundred sixty-three thousand, five hundred one".