128817887 has 8 divisors (see below), whose sum is σ = 141315840. Its totient is φ = 116451160.

The previous prime is 128817883. The next prime is 128817907. The reversal of 128817887 is 788718821.

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

It is a cyclic number.

It is not a de Polignac number, because 128817887 - 2² = 128817883 is a prime.

It is a super-2 number, since 2×128817887² = 33188096022289538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128817883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30743 + ... + 34680.

It is an arithmetic number, because the mean of its divisors is an integer number (17664480).

Almost surely, 2^128817887 is an apocalyptic number.

128817887 is a deficient number, since it is larger than the sum of its proper divisors (12497953).

128817887 is a wasteful number, since it uses less digits than its factorization.

128817887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65613.

The product of its digits is 401408, while the sum is 50.

The square root of 128817887 is about 11349.7967823217. The cubic root of 128817887 is about 505.0395511944.

The spelling of 128817887 in words is "one hundred twenty-eight million, eight hundred seventeen thousand, eight hundred eighty-seven".