647898557 has 2 divisors, whose sum is σ = 647898558. Its totient is φ = 647898556.

The previous prime is 647898539. The next prime is 647898571. The reversal of 647898557 is 755898746.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 542610436 + 105288121 = 23294^2 + 10261^2 .

It is a cyclic number.

It is not a de Polignac number, because 647898557 - 2¹⁰ = 647897533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 647898496 and 647898505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647898257) 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, 323949278 + 323949279.

It is an arithmetic number, because the mean of its divisors is an integer number (323949279).

Almost surely, 2^647898557 is an apocalyptic number.

It is an amenable number.

647898557 is a deficient number, since it is larger than the sum of its proper divisors (1).

647898557 is an equidigital number, since it uses as much as digits as its factorization.

647898557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16934400, while the sum is 59.

The square root of 647898557 is about 25453.8515160280. The cubic root of 647898557 is about 865.3045836170.

The spelling of 647898557 in words is "six hundred forty-seven million, eight hundred ninety-eight thousand, five hundred fifty-seven".