643221300349 has 2 divisors, whose sum is σ = 643221300350. Its totient is φ = 643221300348.

The previous prime is 643221300251. The next prime is 643221300367. The reversal of 643221300349 is 943003122346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643175128324 + 46172025 = 801982^2 + 6795^2 .

It is a cyclic number.

It is not a de Polignac number, because 643221300349 - 2¹³ = 643221292157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643221300049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321610650174 + 321610650175.

It is an arithmetic number, because the mean of its divisors is an integer number (321610650175).

Almost surely, 2^643221300349 is an apocalyptic number.

It is an amenable number.

643221300349 is a deficient number, since it is larger than the sum of its proper divisors (1).

643221300349 is an equidigital number, since it uses as much as digits as its factorization.

643221300349 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 37.

The spelling of 643221300349 in words is "six hundred forty-three billion, two hundred twenty-one million, three hundred thousand, three hundred forty-nine".