6621138 has 12 divisors (see below), whose sum is σ = 14345838. Its totient is φ = 2207040.

The previous prime is 6621137. The next prime is 6621151. The reversal of 6621138 is 8311266.

6621138 is a `hidden beast` number, since 6 + 621 + 1 + 38 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3908529 + 2712609 = 1977^2 + 1647^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6621137) 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 5 ways as a sum of consecutive naturals, for example, 183903 + ... + 183938.

Almost surely, 2^6621138 is an apocalyptic number.

6621138 is an abundant number, since it is smaller than the sum of its proper divisors (7724700).

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

6621138 is a wasteful number, since it uses less digits than its factorization.

6621138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367849 (or 367846 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 6621138 is about 2573.1572046807. The cubic root of 6621138 is about 187.7777855843. Note that the first 4 decimals are identical.

The spelling of 6621138 in words is "six million, six hundred twenty-one thousand, one hundred thirty-eight".