404128789 has 4 divisors (see below), whose sum is σ = 404169280. Its totient is φ = 404088300.

The previous prime is 404128757. The next prime is 404128799. The reversal of 404128789 is 987821404.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 404128789 - 2⁵ = 404128757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404128799) 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, 6532 + ... + 29170.

It is an arithmetic number, because the mean of its divisors is an integer number (101042320).

Almost surely, 2^404128789 is an apocalyptic number.

It is an amenable number.

404128789 is a deficient number, since it is larger than the sum of its proper divisors (40491).

404128789 is a wasteful number, since it uses less digits than its factorization.

404128789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40490.

The product of its (nonzero) digits is 129024, while the sum is 43.

The square root of 404128789 is about 20102.9547330734. The cubic root of 404128789 is about 739.3327251213.

The spelling of 404128789 in words is "four hundred four million, one hundred twenty-eight thousand, seven hundred eighty-nine".