128999507 has 24 divisors (see below), whose sum is σ = 162370656. Its totient is φ = 101582208.

The previous prime is 128999503. The next prime is 128999539. The reversal of 128999507 is 705999821.

It is a happy number.

It is not a de Polignac number, because 128999507 - 2² = 128999503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128999503) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 199058 + ... + 199704.

It is an arithmetic number, because the mean of its divisors is an integer number (6765444).

Almost surely, 2^128999507 is an apocalyptic number.

128999507 is a deficient number, since it is larger than the sum of its proper divisors (33371149).

128999507 is a wasteful number, since it uses less digits than its factorization.

128999507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987 (or 980 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 50.

The square root of 128999507 is about 11357.7949884650. The cubic root of 128999507 is about 505.2767910462.

The spelling of 128999507 in words is "one hundred twenty-eight million, nine hundred ninety-nine thousand, five hundred seven".