128871866 has 8 divisors (see below), whose sum is σ = 204678900. Its totient is φ = 60645568.

The previous prime is 128871863. The next prime is 128871893. The reversal of 128871866 is 668178821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 128346241 + 525625 = 11329^2 + 725^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 128871866.

It is not an unprimeable number, because it can be changed into a prime (128871863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1895141 + ... + 1895208.

Almost surely, 2^128871866 is an apocalyptic number.

128871866 is a deficient number, since it is larger than the sum of its proper divisors (75807034).

128871866 is a wasteful number, since it uses less digits than its factorization.

128871866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3790368.

The product of its digits is 258048, while the sum is 47.

The square root of 128871866 is about 11352.1745053536. The cubic root of 128871866 is about 505.1100841605.

The spelling of 128871866 in words is "one hundred twenty-eight million, eight hundred seventy-one thousand, eight hundred sixty-six".