647661473 has 2 divisors, whose sum is σ = 647661474. Its totient is φ = 647661472.

The previous prime is 647661407. The next prime is 647661481. The reversal of 647661473 is 374166746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624400144 + 23261329 = 24988^2 + 4823^2 .

It is a cyclic number.

It is not a de Polignac number, because 647661473 - 2¹⁰ = 647660449 is a prime.

It is not a weakly prime, because it can be changed into another prime (647661403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323830736 + 323830737.

It is an arithmetic number, because the mean of its divisors is an integer number (323830737).

Almost surely, 2^647661473 is an apocalyptic number.

It is an amenable number.

647661473 is a deficient number, since it is larger than the sum of its proper divisors (1).

647661473 is an equidigital number, since it uses as much as digits as its factorization.

647661473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 44.

The square root of 647661473 is about 25449.1939558014. The cubic root of 647661473 is about 865.1990244478.

The spelling of 647661473 in words is "six hundred forty-seven million, six hundred sixty-one thousand, four hundred seventy-three".