128421311 has 2 divisors, whose sum is σ = 128421312. Its totient is φ = 128421310.

The previous prime is 128421301. The next prime is 128421317. The reversal of 128421311 is 113124821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128421311 - 2¹⁰ = 128420287 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128421317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64210655 + 64210656.

It is an arithmetic number, because the mean of its divisors is an integer number (64210656).

Almost surely, 2^128421311 is an apocalyptic number.

128421311 is a deficient number, since it is larger than the sum of its proper divisors (1).

128421311 is an equidigital number, since it uses as much as digits as its factorization.

128421311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 23.

The square root of 128421311 is about 11332.3126942385. The cubic root of 128421311 is about 504.5207504423.

The spelling of 128421311 in words is "one hundred twenty-eight million, four hundred twenty-one thousand, three hundred eleven".