321661736791 has 2 divisors, whose sum is σ = 321661736792. Its totient is φ = 321661736790.

The previous prime is 321661736779. The next prime is 321661736807. The reversal of 321661736791 is 197637166123.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 321661736791 - 2¹¹ = 321661734743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321661736701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160830868395 + 160830868396.

It is an arithmetic number, because the mean of its divisors is an integer number (160830868396).

Almost surely, 2^321661736791 is an apocalyptic number.

321661736791 is a deficient number, since it is larger than the sum of its proper divisors (1).

321661736791 is an equidigital number, since it uses as much as digits as its factorization.

321661736791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 52.

The spelling of 321661736791 in words is "three hundred twenty-one billion, six hundred sixty-one million, seven hundred thirty-six thousand, seven hundred ninety-one".