6404989 has 4 divisors (see below), whose sum is σ = 6410880. Its totient is φ = 6399100.

The previous prime is 6404987. The next prime is 6405011. The reversal of 6404989 is 9894046.

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 6404989 - 2¹ = 6404987 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 (6404987) 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, 787 + ... + 3664.

It is an arithmetic number, because the mean of its divisors is an integer number (1602720).

Almost surely, 2^6404989 is an apocalyptic number.

It is an amenable number.

6404989 is a deficient number, since it is larger than the sum of its proper divisors (5891).

6404989 is a wasteful number, since it uses less digits than its factorization.

6404989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5890.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 6404989 is about 2530.8079737507. The cubic root of 6404989 is about 185.7117843281.

The spelling of 6404989 in words is "six million, four hundred four thousand, nine hundred eighty-nine".