6405644 has 12 divisors (see below), whose sum is σ = 12811344. Its totient is φ = 2745264.

The previous prime is 6405643. The next prime is 6405647. The reversal of 6405644 is 4465046.

6405644 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (6405643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114359 + ... + 114414.

It is an arithmetic number, because the mean of its divisors is an integer number (1067612).

Almost surely, 2^6405644 is an apocalyptic number.

It is an amenable number.

6405644 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6405644 is a wasteful number, since it uses less digits than its factorization.

6405644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228784 (or 228782 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 6405644 is about 2530.9373757563. The cubic root of 6405644 is about 185.7181146576.

The spelling of 6405644 in words is "six million, four hundred five thousand, six hundred forty-four".