6638820 has 24 divisors (see below), whose sum is σ = 18588864. Its totient is φ = 1770336.

The previous prime is 6638803. The next prime is 6638851. The reversal of 6638820 is 288366.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 55264 + ... + 55383.

It is an arithmetic number, because the mean of its divisors is an integer number (774536).

Almost surely, 2^6638820 is an apocalyptic number.

6638820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6638820 is an abundant number, since it is smaller than the sum of its proper divisors (11950044).

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

6638820 is a wasteful number, since it uses less digits than its factorization.

6638820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110659 (or 110657 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 6638820 is about 2576.5907707667. The cubic root of 6638820 is about 187.9447929040.

The spelling of 6638820 in words is "six million, six hundred thirty-eight thousand, eight hundred twenty".