7638128789 has 2 divisors, whose sum is σ = 7638128790. Its totient is φ = 7638128788.

The previous prime is 7638128777. The next prime is 7638128819. The reversal of 7638128789 is 9878218367.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6812026225 + 826102564 = 82535^2 + 28742^2 .

It is a cyclic number.

It is not a de Polignac number, because 7638128789 - 2¹² = 7638124693 is a prime.

It is a super-2 number, since 2×7638128789² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7638128759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3819064394 + 3819064395.

It is an arithmetic number, because the mean of its divisors is an integer number (3819064395).

Almost surely, 2^7638128789 is an apocalyptic number.

It is an amenable number.

7638128789 is a deficient number, since it is larger than the sum of its proper divisors (1).

7638128789 is an equidigital number, since it uses as much as digits as its factorization.

7638128789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8128512, while the sum is 59.

The square root of 7638128789 is about 87396.3888784886. The cubic root of 7638128789 is about 1969.3775928060.

The spelling of 7638128789 in words is "seven billion, six hundred thirty-eight million, one hundred twenty-eight thousand, seven hundred eighty-nine".