128440187 has 2 divisors, whose sum is σ = 128440188. Its totient is φ = 128440186.

The previous prime is 128440177. The next prime is 128440229. The reversal of 128440187 is 781044821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128440187 - 2¹⁰ = 128439163 is a prime.

It is a Chen prime.

It is equal to p_7294553 and since 128440187 and 7294553 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (128440177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64220093 + 64220094.

It is an arithmetic number, because the mean of its divisors is an integer number (64220094).

Almost surely, 2^128440187 is an apocalyptic number.

128440187 is a deficient number, since it is larger than the sum of its proper divisors (1).

128440187 is an equidigital number, since it uses as much as digits as its factorization.

128440187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 128440187 is about 11333.1455033455. The cubic root of 128440187 is about 504.5454682171.

The spelling of 128440187 in words is "one hundred twenty-eight million, four hundred forty thousand, one hundred eighty-seven".