128923849 has 4 divisors (see below), whose sum is σ = 128946564. Its totient is φ = 128901136.

The previous prime is 128923843. The next prime is 128923853. The reversal of 128923849 is 948329821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 63313849 + 65610000 = 7957^2 + 8100^2 .

It is a cyclic number.

It is not a de Polignac number, because 128923849 - 2³ = 128923841 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 128923799 and 128923808.

It is not an unprimeable number, because it can be changed into a prime (128923841) 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, 5319 + ... + 16915.

It is an arithmetic number, because the mean of its divisors is an integer number (32236641).

Almost surely, 2^128923849 is an apocalyptic number.

It is an amenable number.

128923849 is a deficient number, since it is larger than the sum of its proper divisors (22715).

128923849 is a wasteful number, since it uses less digits than its factorization.

128923849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22714.

The product of its digits is 248832, while the sum is 46.

The square root of 128923849 is about 11354.4638358665. The cubic root of 128923849 is about 505.1779903909.

The spelling of 128923849 in words is "one hundred twenty-eight million, nine hundred twenty-three thousand, eight hundred forty-nine".