6638875729 has 2 divisors, whose sum is σ = 6638875730. Its totient is φ = 6638875728.

The previous prime is 6638875577. The next prime is 6638875741. The reversal of 6638875729 is 9275788366.

6638875729 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., 6601237504 + 37638225 = 81248^2 + 6135^2 .

It is a cyclic number.

It is not a de Polignac number, because 6638875729 - 2¹⁷ = 6638744657 is a prime.

It is not a weakly prime, because it can be changed into another prime (6638875129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3319437864 + 3319437865.

It is an arithmetic number, because the mean of its divisors is an integer number (3319437865).

Almost surely, 2^6638875729 is an apocalyptic number.

It is an amenable number.

6638875729 is a deficient number, since it is larger than the sum of its proper divisors (1).

6638875729 is an equidigital number, since it uses as much as digits as its factorization.

6638875729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30481920, while the sum is 61.

The square root of 6638875729 is about 81479.2963212128. The cubic root of 6638875729 is about 1879.4531879795.

The spelling of 6638875729 in words is "six billion, six hundred thirty-eight million, eight hundred seventy-five thousand, seven hundred twenty-nine".