128381587 has 2 divisors, whose sum is σ = 128381588. Its totient is φ = 128381586.

The previous prime is 128381563. The next prime is 128381593. The reversal of 128381587 is 785183821.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128381587 is a prime.

It is not a weakly prime, because it can be changed into another prime (128381597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64190793 + 64190794.

It is an arithmetic number, because the mean of its divisors is an integer number (64190794).

Almost surely, 2^128381587 is an apocalyptic number.

128381587 is a deficient number, since it is larger than the sum of its proper divisors (1).

128381587 is an equidigital number, since it uses as much as digits as its factorization.

128381587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 107520, while the sum is 43.

The square root of 128381587 is about 11330.5598714274. The cubic root of 128381587 is about 504.4687246818.

The spelling of 128381587 in words is "one hundred twenty-eight million, three hundred eighty-one thousand, five hundred eighty-seven".