128716631 has 2 divisors, whose sum is σ = 128716632. Its totient is φ = 128716630.

The previous prime is 128716591. The next prime is 128716633. The reversal of 128716631 is 136617821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128716631 - 2¹⁰ = 128715607 is a prime.

It is a super-2 number, since 2×128716631² = 33135942191980322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 128716633, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 128716591 and 128716600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128716633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64358315 + 64358316.

It is an arithmetic number, because the mean of its divisors is an integer number (64358316).

Almost surely, 2^128716631 is an apocalyptic number.

128716631 is a deficient number, since it is larger than the sum of its proper divisors (1).

128716631 is an equidigital number, since it uses as much as digits as its factorization.

128716631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 128716631 is about 11345.3352087984. The cubic root of 128716631 is about 504.9071894270.

The spelling of 128716631 in words is "one hundred twenty-eight million, seven hundred sixteen thousand, six hundred thirty-one".