6640138 has 8 divisors (see below), whose sum is σ = 10281600. Its totient is φ = 3212940.

The previous prime is 6640129. The next prime is 6640157. The reversal of 6640138 is 8310466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53488 + ... + 53611.

It is an arithmetic number, because the mean of its divisors is an integer number (1285200).

Almost surely, 2^6640138 is an apocalyptic number.

6640138 is a deficient number, since it is larger than the sum of its proper divisors (3641462).

6640138 is a wasteful number, since it uses less digits than its factorization.

6640138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107132.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 6640138 is about 2576.8465223990. The cubic root of 6640138 is about 187.9572295944.

It can be divided in two parts, 66 and 40138, that added together give a palindrome (40204).

The spelling of 6640138 in words is "six million, six hundred forty thousand, one hundred thirty-eight".