128609994 has 16 divisors (see below), whose sum is σ = 260320032. Its totient is φ = 42353328.

The previous prime is 128609977. The next prime is 128610011. The reversal of 128609994 is 499906821.

It is an interprime number because it is at equal distance from previous prime (128609977) and next prime (128610011).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128629 + ... + 129624.

It is an arithmetic number, because the mean of its divisors is an integer number (16270002).

Almost surely, 2^128609994 is an apocalyptic number.

128609994 is an abundant number, since it is smaller than the sum of its proper divisors (131710038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128609994 is a wasteful number, since it uses less digits than its factorization.

128609994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258341.

The product of its (nonzero) digits is 279936, while the sum is 48.

The square root of 128609994 is about 11340.6346383260. The cubic root of 128609994 is about 504.7677185520.

The spelling of 128609994 in words is "one hundred twenty-eight million, six hundred nine thousand, nine hundred ninety-four".