404648639 has 6 divisors (see below), whose sum is σ = 414760560. Its totient is φ = 394777520.

The previous prime is 404648633. The next prime is 404648669. The reversal of 404648639 is 936846404.

It is not a de Polignac number, because 404648639 - 2²⁴ = 387871423 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 404648639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404648633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 118679 + ... + 122040.

It is an arithmetic number, because the mean of its divisors is an integer number (69126760).

Almost surely, 2^404648639 is an apocalyptic number.

404648639 is a deficient number, since it is larger than the sum of its proper divisors (10111921).

404648639 is an equidigital number, since it uses as much as digits as its factorization.

404648639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240801 (or 240760 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 44.

The square root of 404648639 is about 20115.8802690809. The cubic root of 404648639 is about 739.6496021880.

The spelling of 404648639 in words is "four hundred four million, six hundred forty-eight thousand, six hundred thirty-nine".