647771243269 has 2 divisors, whose sum is σ = 647771243270. Its totient is φ = 647771243268.

The previous prime is 647771243257. The next prime is 647771243321. The reversal of 647771243269 is 962342177746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 643436601025 + 4334642244 = 802145^2 + 65838^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647771243269 is a prime.

It is a super-2 number, since 2×647771243269² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647771243239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323885621634 + 323885621635.

It is an arithmetic number, because the mean of its divisors is an integer number (323885621635).

Almost surely, 2^647771243269 is an apocalyptic number.

It is an amenable number.

647771243269 is a deficient number, since it is larger than the sum of its proper divisors (1).

647771243269 is an equidigital number, since it uses as much as digits as its factorization.

647771243269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21337344, while the sum is 58.

The spelling of 647771243269 in words is "six hundred forty-seven billion, seven hundred seventy-one million, two hundred forty-three thousand, two hundred sixty-nine".