6644963 has 4 divisors (see below), whose sum is σ = 7156128. Its totient is φ = 6133800.

The previous prime is 6644959. The next prime is 6644969. The reversal of 6644963 is 3694466.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3694466 = 2 ⋅1847233.

It is a cyclic number.

It is not a de Polignac number, because 6644963 - 2² = 6644959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6644969) 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, 255563 + ... + 255588.

It is an arithmetic number, because the mean of its divisors is an integer number (1789032).

Almost surely, 2^6644963 is an apocalyptic number.

6644963 is a deficient number, since it is larger than the sum of its proper divisors (511165).

6644963 is a wasteful number, since it uses less digits than its factorization.

6644963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511164.

The product of its digits is 93312, while the sum is 38.

The square root of 6644963 is about 2577.7825742293. The cubic root of 6644963 is about 188.0027444144.

The spelling of 6644963 in words is "six million, six hundred forty-four thousand, nine hundred sixty-three".