6404641 has 4 divisors (see below), whose sum is σ = 6411312. Its totient is φ = 6397972.

The previous prime is 6404639. The next prime is 6404647. The reversal of 6404641 is 1464046.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1464046 = 2 ⋅732023.

It is a cyclic number.

It is not a de Polignac number, because 6404641 - 2¹ = 6404639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6404647) 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, 1591 + ... + 3916.

It is an arithmetic number, because the mean of its divisors is an integer number (1602828).

Almost surely, 2^6404641 is an apocalyptic number.

It is an amenable number.

6404641 is a deficient number, since it is larger than the sum of its proper divisors (6671).

6404641 is a wasteful number, since it uses less digits than its factorization.

6404641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6670.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 6404641 is about 2530.7392200699. The cubic root of 6404641 is about 185.7084208630.

Adding to 6404641 its reverse (1464046), we get a palindrome (7868687).

The spelling of 6404641 in words is "six million, four hundred four thousand, six hundred forty-one".