647771245321 has 2 divisors, whose sum is σ = 647771245322. Its totient is φ = 647771245320.

The previous prime is 647771245309. The next prime is 647771245369. The reversal of 647771245321 is 123542177746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640422469696 + 7348775625 = 800264^2 + 85725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647771245321 is a prime.

It is not a weakly prime, because it can be changed into another prime (647771245391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323885622660 + 323885622661.

It is an arithmetic number, because the mean of its divisors is an integer number (323885622661).

Almost surely, 2^647771245321 is an apocalyptic number.

It is an amenable number.

647771245321 is a deficient number, since it is larger than the sum of its proper divisors (1).

647771245321 is an equidigital number, since it uses as much as digits as its factorization.

647771245321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1975680, while the sum is 49.

The spelling of 647771245321 in words is "six hundred forty-seven billion, seven hundred seventy-one million, two hundred forty-five thousand, three hundred twenty-one".