5128135421 has 2 divisors, whose sum is σ = 5128135422. Its totient is φ = 5128135420.

The previous prime is 5128135417. The next prime is 5128135423. The reversal of 5128135421 is 1245318215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5128135321 + 100 = 71611^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 5128135421 - 2² = 5128135417 is a prime.

It is a super-2 number, since 2×5128135421² = 52595545792229694482, which contains 22 as substring.

Together with 5128135423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5128135423) 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, 2564067710 + 2564067711.

It is an arithmetic number, because the mean of its divisors is an integer number (2564067711).

Almost surely, 2^5128135421 is an apocalyptic number.

It is an amenable number.

5128135421 is a deficient number, since it is larger than the sum of its proper divisors (1).

5128135421 is an equidigital number, since it uses as much as digits as its factorization.

5128135421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9600, while the sum is 32.

The square root of 5128135421 is about 71611.0006982168. Note that the first 3 decimals coincide. The cubic root of 5128135421 is about 1724.4601456771.

The spelling of 5128135421 in words is "five billion, one hundred twenty-eight million, one hundred thirty-five thousand, four hundred twenty-one".