720202211221 has 2 divisors, whose sum is σ = 720202211222. Its totient is φ = 720202211220.

The previous prime is 720202211177. The next prime is 720202211243. The reversal of 720202211221 is 122112202027.

It is an a-pointer prime, because the next prime (720202211243) can be obtained adding 720202211221 to its sum of digits (22).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 714954802500 + 5247408721 = 845550^2 + 72439^2 .

It is an emirp because it is prime and its reverse (122112202027) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 720202211221 - 2¹⁷ = 720202080149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 720202211192 and 720202211201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (720202211321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360101105610 + 360101105611.

It is an arithmetic number, because the mean of its divisors is an integer number (360101105611).

Almost surely, 2^720202211221 is an apocalyptic number.

It is an amenable number.

720202211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

720202211221 is an equidigital number, since it uses as much as digits as its factorization.

720202211221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

Adding to 720202211221 its reverse (122112202027), we get a palindrome (842314413248).

The spelling of 720202211221 in words is "seven hundred twenty billion, two hundred two million, two hundred eleven thousand, two hundred twenty-one".