128663890 has 8 divisors (see below), whose sum is σ = 231595020. Its totient is φ = 51465552.

The previous prime is 128663881. The next prime is 128663891. The reversal of 128663890 is 98366821.

It can be written as a sum of positive squares in 2 ways, for example, as 123854641 + 4809249 = 11129^2 + 2193^2 .

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

It is not an unprimeable number, because it can be changed into a prime (128663891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6433185 + ... + 6433204.

Almost surely, 2^128663890 is an apocalyptic number.

128663890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128663890 is a deficient number, since it is larger than the sum of its proper divisors (102931130).

128663890 is a wasteful number, since it uses less digits than its factorization.

128663890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12866396.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 128663890 is about 11343.0106232869. The cubic root of 128663890 is about 504.8382189354.

The spelling of 128663890 in words is "one hundred twenty-eight million, six hundred sixty-three thousand, eight hundred ninety".