726205421 has 2 divisors, whose sum is σ = 726205422. Its totient is φ = 726205420.

The previous prime is 726205397. The next prime is 726205423. The reversal of 726205421 is 124502627.

It is a happy number.

726205421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 503778025 + 222427396 = 22445^2 + 14914^2 .

It is an emirp because it is prime and its reverse (124502627) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 726205421 - 2¹⁸ = 725943277 is a prime.

Together with 726205423, 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 (726205423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 363102710 + 363102711.

It is an arithmetic number, because the mean of its divisors is an integer number (363102711).

Almost surely, 2^726205421 is an apocalyptic number.

It is an amenable number.

726205421 is a deficient number, since it is larger than the sum of its proper divisors (1).

726205421 is an equidigital number, since it uses as much as digits as its factorization.

726205421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 726205421 is about 26948.1988451919. The cubic root of 726205421 is about 898.8484948245.

The spelling of 726205421 in words is "seven hundred twenty-six million, two hundred five thousand, four hundred twenty-one".