128687687 has 2 divisors, whose sum is σ = 128687688. Its totient is φ = 128687686.

The previous prime is 128687683. The next prime is 128687693. The reversal of 128687687 is 786786821.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128687687 - 2² = 128687683 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128687683) 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, 64343843 + 64343844.

It is an arithmetic number, because the mean of its divisors is an integer number (64343844).

Almost surely, 2^128687687 is an apocalyptic number.

128687687 is a deficient number, since it is larger than the sum of its proper divisors (1).

128687687 is an equidigital number, since it uses as much as digits as its factorization.

128687687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1806336, while the sum is 53.

The square root of 128687687 is about 11344.0595467408. The cubic root of 128687687 is about 504.8693410954.

The spelling of 128687687 in words is "one hundred twenty-eight million, six hundred eighty-seven thousand, six hundred eighty-seven".