6631666409 has 2 divisors, whose sum is σ = 6631666410. Its totient is φ = 6631666408.

The previous prime is 6631666277. The next prime is 6631666417. The reversal of 6631666409 is 9046661366.

6631666409 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5202448384 + 1429218025 = 72128^2 + 37805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6631666409 is a prime.

It is not a weakly prime, because it can be changed into another prime (6631666469) 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, 3315833204 + 3315833205.

It is an arithmetic number, because the mean of its divisors is an integer number (3315833205).

Almost surely, 2^6631666409 is an apocalyptic number.

It is an amenable number.

6631666409 is a deficient number, since it is larger than the sum of its proper divisors (1).

6631666409 is an equidigital number, since it uses as much as digits as its factorization.

6631666409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 839808, while the sum is 47.

The square root of 6631666409 is about 81435.0441087865. The cubic root of 6631666409 is about 1878.7726266124.

The spelling of 6631666409 in words is "six billion, six hundred thirty-one million, six hundred sixty-six thousand, four hundred nine".