6628381 has 4 divisors (see below), whose sum is σ = 6633952. Its totient is φ = 6622812.

The previous prime is 6628379. The next prime is 6628403. The reversal of 6628381 is 1838266.

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.

It is a cyclic number.

It is not a de Polignac number, because 6628381 - 2¹ = 6628379 is a prime.

It is a super-2 number, since 2×6628381² = 87870869362322, which contains 22 as substring.

It is a Duffinian number.

6628381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6628781) 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, 201 + ... + 3646.

It is an arithmetic number, because the mean of its divisors is an integer number (1658488).

Almost surely, 2^6628381 is an apocalyptic number.

It is an amenable number.

6628381 is a deficient number, since it is larger than the sum of its proper divisors (5571).

6628381 is a wasteful number, since it uses less digits than its factorization.

6628381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5570.

The product of its digits is 13824, while the sum is 34.

The square root of 6628381 is about 2574.5642349726. The cubic root of 6628381 is about 187.8462319684.

The spelling of 6628381 in words is "six million, six hundred twenty-eight thousand, three hundred eighty-one".