6643577429 has 2 divisors, whose sum is σ = 6643577430. Its totient is φ = 6643577428.

The previous prime is 6643577387. The next prime is 6643577453. The reversal of 6643577429 is 9247753466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5883196804 + 760380625 = 76702^2 + 27575^2 .

It is a cyclic number.

It is not a de Polignac number, because 6643577429 - 2⁸ = 6643577173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6643577459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3321788714 + 3321788715.

It is an arithmetic number, because the mean of its divisors is an integer number (3321788715).

Almost surely, 2^6643577429 is an apocalyptic number.

It is an amenable number.

6643577429 is a deficient number, since it is larger than the sum of its proper divisors (1).

6643577429 is an equidigital number, since it uses as much as digits as its factorization.

6643577429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7620480, while the sum is 53.

The square root of 6643577429 is about 81508.1433293631. The cubic root of 6643577429 is about 1879.8967640799.

The spelling of 6643577429 in words is "six billion, six hundred forty-three million, five hundred seventy-seven thousand, four hundred twenty-nine".