647771243321 has 2 divisors, whose sum is σ = 647771243322. Its totient is φ = 647771243320.

The previous prime is 647771243269. The next prime is 647771243347. The reversal of 647771243321 is 123342177746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 644359398400 + 3411844921 = 802720^2 + 58411^2 .

It is a cyclic number.

It is not a de Polignac number, because 647771243321 - 2⁶ = 647771243257 is a prime.

It is not a weakly prime, because it can be changed into another prime (647771245321) 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, 323885621660 + 323885621661.

It is an arithmetic number, because the mean of its divisors is an integer number (323885621661).

Almost surely, 2^647771243321 is an apocalyptic number.

It is an amenable number.

647771243321 is a deficient number, since it is larger than the sum of its proper divisors (1).

647771243321 is an equidigital number, since it uses as much as digits as its factorization.

647771243321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1185408, while the sum is 47.

The spelling of 647771243321 in words is "six hundred forty-seven billion, seven hundred seventy-one million, two hundred forty-three thousand, three hundred twenty-one".