128405791 has 2 divisors, whose sum is σ = 128405792. Its totient is φ = 128405790.

The previous prime is 128405789. The next prime is 128405801. The reversal of 128405791 is 197504821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128405791 - 2¹ = 128405789 is a prime.

Together with 128405789, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 128405791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128403791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64202895 + 64202896.

It is an arithmetic number, because the mean of its divisors is an integer number (64202896).

Almost surely, 2^128405791 is an apocalyptic number.

128405791 is a deficient number, since it is larger than the sum of its proper divisors (1).

128405791 is an equidigital number, since it uses as much as digits as its factorization.

128405791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 128405791 is about 11331.6279059983. The cubic root of 128405791 is about 504.5004254733.

The spelling of 128405791 in words is "one hundred twenty-eight million, four hundred five thousand, seven hundred ninety-one".