128562391 has 2 divisors, whose sum is σ = 128562392. Its totient is φ = 128562390.

The previous prime is 128562377. The next prime is 128562403. The reversal of 128562391 is 193265821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128562391 - 2⁵ = 128562359 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128562391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128562311) 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, 64281195 + 64281196.

It is an arithmetic number, because the mean of its divisors is an integer number (64281196).

Almost surely, 2^128562391 is an apocalyptic number.

128562391 is a deficient number, since it is larger than the sum of its proper divisors (1).

128562391 is an equidigital number, since it uses as much as digits as its factorization.

128562391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The square root of 128562391 is about 11338.5356638324. The cubic root of 128562391 is about 504.7054335456.

The spelling of 128562391 in words is "one hundred twenty-eight million, five hundred sixty-two thousand, three hundred ninety-one".