726591020210221 has 2 divisors, whose sum is σ = 726591020210222. Its totient is φ = 726591020210220.

The previous prime is 726591020210177. The next prime is 726591020210227. The reversal of 726591020210221 is 122012020195627.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 508164937440196 + 218426082770025 = 22542514^2 + 14779245^2 .

It is an emirp because it is prime and its reverse (122012020195627) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 726591020210221 - 2⁷ = 726591020210093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (726591020210227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 363295510105110 + 363295510105111.

It is an arithmetic number, because the mean of its divisors is an integer number (363295510105111).

Almost surely, 2^{726591020210221} is an apocalyptic number.

It is an amenable number.

726591020210221 is a deficient number, since it is larger than the sum of its proper divisors (1).

726591020210221 is an equidigital number, since it uses as much as digits as its factorization.

726591020210221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 726591020210221 in words is "seven hundred twenty-six trillion, five hundred ninety-one billion, twenty million, two hundred ten thousand, two hundred twenty-one".