321240100243261 has 2 divisors, whose sum is σ = 321240100243262. Its totient is φ = 321240100243260.

The previous prime is 321240100243189. The next prime is 321240100243297. The reversal of 321240100243261 is 162342001042123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 295220093080900 + 26020007162361 = 17181970^2 + 5100981^2 .

It is a cyclic number.

It is not a de Polignac number, because 321240100243261 - 2²⁹ = 321239563372349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321240100243661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160620050121630 + 160620050121631.

It is an arithmetic number, because the mean of its divisors is an integer number (160620050121631).

Almost surely, 2^{321240100243261} is an apocalyptic number.

It is an amenable number.

321240100243261 is a deficient number, since it is larger than the sum of its proper divisors (1).

321240100243261 is an equidigital number, since it uses as much as digits as its factorization.

321240100243261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 31.

Adding to 321240100243261 its reverse (162342001042123), we get a palindrome (483582101285384).

The spelling of 321240100243261 in words is "three hundred twenty-one trillion, two hundred forty billion, one hundred million, two hundred forty-three thousand, two hundred sixty-one".