6639530 has 16 divisors (see below), whose sum is σ = 12030120. Its totient is φ = 2638272.

The previous prime is 6639527. The next prime is 6639533. The reversal of 6639530 is 359366.

It is an interprime number because it is at equal distance from previous prime (6639527) and next prime (6639533).

It can be written as a sum of positive squares in 4 ways, for example, as 6355441 + 284089 = 2521^2 + 533^2 .

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6639533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 545 + ... + 3684.

Almost surely, 2^6639530 is an apocalyptic number.

6639530 is a deficient number, since it is larger than the sum of its proper divisors (5390590).

6639530 is a wasteful number, since it uses less digits than its factorization.

6639530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4393.

The product of its (nonzero) digits is 14580, while the sum is 32.

The square root of 6639530 is about 2576.7285460444. The cubic root of 6639530 is about 187.9514926913.

The spelling of 6639530 in words is "six million, six hundred thirty-nine thousand, five hundred thirty".