128392813 has 2 divisors, whose sum is σ = 128392814. Its totient is φ = 128392812.

The previous prime is 128392811. The next prime is 128392819. The reversal of 128392813 is 318293821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117548964 + 10843849 = 10842^2 + 3293^2 .

It is a cyclic number.

It is not a de Polignac number, because 128392813 - 2¹ = 128392811 is a prime.

Together with 128392811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128392811) 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, 64196406 + 64196407.

It is an arithmetic number, because the mean of its divisors is an integer number (64196407).

Almost surely, 2^128392813 is an apocalyptic number.

It is an amenable number.

128392813 is a deficient number, since it is larger than the sum of its proper divisors (1).

128392813 is an equidigital number, since it uses as much as digits as its factorization.

128392813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The square root of 128392813 is about 11331.0552465337. The cubic root of 128392813 is about 504.4834282464.

It can be divided in two parts, 128 and 392813, that added together give a triangular number (392941 = T₈₈₆).

The spelling of 128392813 in words is "one hundred twenty-eight million, three hundred ninety-two thousand, eight hundred thirteen".