6631221329 has 2 divisors, whose sum is σ = 6631221330. Its totient is φ = 6631221328.

The previous prime is 6631221319. The next prime is 6631221419. The reversal of 6631221329 is 9231221366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6233418304 + 397803025 = 78952^2 + 19945^2 .

It is a cyclic number.

It is not a de Polignac number, because 6631221329 - 2⁴ = 6631221313 is a prime.

It is not a weakly prime, because it can be changed into another prime (6631221319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3315610664 + 3315610665.

It is an arithmetic number, because the mean of its divisors is an integer number (3315610665).

Almost surely, 2^6631221329 is an apocalyptic number.

It is an amenable number.

6631221329 is a deficient number, since it is larger than the sum of its proper divisors (1).

6631221329 is an equidigital number, since it uses as much as digits as its factorization.

6631221329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 35.

The square root of 6631221329 is about 81432.3113327873. The cubic root of 6631221329 is about 1878.7305948024.

The spelling of 6631221329 in words is "six billion, six hundred thirty-one million, two hundred twenty-one thousand, three hundred twenty-nine".