6403646549 has 2 divisors, whose sum is σ = 6403646550. Its totient is φ = 6403646548.

The previous prime is 6403646521. The next prime is 6403646567. The reversal of 6403646549 is 9456463046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3841768324 + 2561878225 = 61982^2 + 50615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6403646549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6403646519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3201823274 + 3201823275.

It is an arithmetic number, because the mean of its divisors is an integer number (3201823275).

Almost surely, 2^6403646549 is an apocalyptic number.

It is an amenable number.

6403646549 is a deficient number, since it is larger than the sum of its proper divisors (1).

6403646549 is an equidigital number, since it uses as much as digits as its factorization.

6403646549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1866240, while the sum is 47.

The square root of 6403646549 is about 80022.7876857586. The cubic root of 6403646549 is about 1856.9880869351.

The spelling of 6403646549 in words is "six billion, four hundred three million, six hundred forty-six thousand, five hundred forty-nine".