6638740 has 12 divisors (see below), whose sum is σ = 13941396. Its totient is φ = 2655488.

The previous prime is 6638701. The next prime is 6638741. The reversal of 6638740 is 478366.

It can be written as a sum of positive squares in 2 ways, for example, as 3694084 + 2944656 = 1922^2 + 1716^2 .

It is a junction number, because it is equal to n+sod(n) for n = 6638696 and 6638705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6638741) 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, 165949 + ... + 165988.

It is an arithmetic number, because the mean of its divisors is an integer number (1161783).

Almost surely, 2^6638740 is an apocalyptic number.

It is an amenable number.

6638740 is an abundant number, since it is smaller than the sum of its proper divisors (7302656).

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

6638740 is a wasteful number, since it uses less digits than its factorization.

6638740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331946 (or 331944 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 6638740 is about 2576.5752463299. The cubic root of 6638740 is about 187.9440379684.

The spelling of 6638740 in words is "six million, six hundred thirty-eight thousand, seven hundred forty".