655320121 has 2 divisors, whose sum is σ = 655320122. Its totient is φ = 655320120.

The previous prime is 655320119. The next prime is 655320151. The reversal of 655320121 is 121023556.

655320121 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., 466560000 + 188760121 = 21600^2 + 13739^2 .

It is a cyclic number.

It is not a de Polignac number, because 655320121 - 2¹ = 655320119 is a prime.

Together with 655320119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (655320101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327660060 + 327660061.

It is an arithmetic number, because the mean of its divisors is an integer number (327660061).

Almost surely, 2^655320121 is an apocalyptic number.

It is an amenable number.

655320121 is a deficient number, since it is larger than the sum of its proper divisors (1).

655320121 is an equidigital number, since it uses as much as digits as its factorization.

655320121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 655320121 is about 25599.2211014320. The cubic root of 655320121 is about 868.5960184211.

Adding to 655320121 its reverse (121023556), we get a palindrome (776343677).

The spelling of 655320121 in words is "six hundred fifty-five million, three hundred twenty thousand, one hundred twenty-one".