6638881 has 4 divisors (see below), whose sum is σ = 6927552. Its totient is φ = 6350212.

The previous prime is 6638851. The next prime is 6638893. The reversal of 6638881 is 1888366.

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.

It is a cyclic number.

It is not a de Polignac number, because 6638881 - 2⁹ = 6638369 is a prime.

It is a super-3 number, since 3×6638881³ (a number of 21 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6638851) 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, 144301 + ... + 144346.

It is an arithmetic number, because the mean of its divisors is an integer number (1731888).

Almost surely, 2^6638881 is an apocalyptic number.

It is an amenable number.

6638881 is a deficient number, since it is larger than the sum of its proper divisors (288671).

6638881 is a wasteful number, since it uses less digits than its factorization.

6638881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288670.

The product of its digits is 55296, while the sum is 40.

The square root of 6638881 is about 2576.6026080869. The cubic root of 6638881 is about 187.9453685383.

The spelling of 6638881 in words is "six million, six hundred thirty-eight thousand, eight hundred eighty-one".