128649379 has 4 divisors (see below), whose sum is σ = 128768176. Its totient is φ = 128530584.

The previous prime is 128649371. The next prime is 128649383. The reversal of 128649379 is 973946821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128649379 - 2³ = 128649371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128649371) 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, 57759 + ... + 59944.

It is an arithmetic number, because the mean of its divisors is an integer number (32192044).

Almost surely, 2^128649379 is an apocalyptic number.

128649379 is a deficient number, since it is larger than the sum of its proper divisors (118797).

128649379 is a wasteful number, since it uses less digits than its factorization.

128649379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118796.

The product of its digits is 653184, while the sum is 49.

The square root of 128649379 is about 11342.3709602534. The cubic root of 128649379 is about 504.8192392957.

The spelling of 128649379 in words is "one hundred twenty-eight million, six hundred forty-nine thousand, three hundred seventy-nine".