6638139 has 16 divisors (see below), whose sum is σ = 10045440. Its totient is φ = 4330440.

The previous prime is 6638131. The next prime is 6638141. The reversal of 6638139 is 9318366.

It is a happy number.

6638139 is a `hidden beast` number, since 6 + 638 + 13 + 9 = 666.

It is not a de Polignac number, because 6638139 - 2³ = 6638131 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6638131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1347 + ... + 3884.

It is an arithmetic number, because the mean of its divisors is an integer number (627840).

Almost surely, 2^6638139 is an apocalyptic number.

6638139 is a deficient number, since it is larger than the sum of its proper divisors (3407301).

6638139 is a wasteful number, since it uses less digits than its factorization.

6638139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5287 (or 5281 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 6638139 is about 2576.4586160076. The cubic root of 6638139 is about 187.9383663211.

The spelling of 6638139 in words is "six million, six hundred thirty-eight thousand, one hundred thirty-nine".