6643619 has 4 divisors (see below), whose sum is σ = 6932496. Its totient is φ = 6354744.

The previous prime is 6643607. The next prime is 6643633. The reversal of 6643619 is 9163466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6643619 - 2²⁰ = 5595043 is a prime.

It is a super-2 number, since 2×6643619² = 88275346834322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6643649) 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, 144404 + ... + 144449.

It is an arithmetic number, because the mean of its divisors is an integer number (1733124).

Almost surely, 2^6643619 is an apocalyptic number.

6643619 is a deficient number, since it is larger than the sum of its proper divisors (288877).

6643619 is a wasteful number, since it uses less digits than its factorization.

6643619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288876.

The product of its digits is 23328, while the sum is 35.

The square root of 6643619 is about 2577.5218718762. The cubic root of 6643619 is about 187.9900685111.

The spelling of 6643619 in words is "six million, six hundred forty-three thousand, six hundred nineteen".