721071361 has 2 divisors, whose sum is σ = 721071362. Its totient is φ = 721071360.

The previous prime is 721071359. The next prime is 721071401. The reversal of 721071361 is 163170127.

721071361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 491730625 + 229340736 = 22175^2 + 15144^2 .

It is an emirp because it is prime and its reverse (163170127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721071361 - 2¹ = 721071359 is a prime.

Together with 721071359, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (721071311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360535680 + 360535681.

It is an arithmetic number, because the mean of its divisors is an integer number (360535681).

Almost surely, 2^721071361 is an apocalyptic number.

It is an amenable number.

721071361 is a deficient number, since it is larger than the sum of its proper divisors (1).

721071361 is an equidigital number, since it uses as much as digits as its factorization.

721071361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 721071361 is about 26852.7719425761. The cubic root of 721071361 is about 896.7252847595.

The spelling of 721071361 in words is "seven hundred twenty-one million, seventy-one thousand, three hundred sixty-one".